http://www.ampmaker.com/infocentre/ Wed, 19 Jun 2013 07:27:32 +0000 MyBB http://www.ampmaker.com/infocentre/thread-116.html Mon, 13 May 2013 15:31:41 -0500 http://www.ampmaker.com/infocentre/thread-116.html
The entries below show the 'bare bones' of the amp construction, in the order a typical amp builder would built the amp:
1) Kit contents listing
2) The PP-36 schematic
3) The layout of hardware on the chassis
4) The circuit layout, with all components and wiring]]>
The entries below show the 'bare bones' of the amp construction, in the order a typical amp builder would built the amp:
1) Kit contents listing
2) The PP-36 schematic
3) The layout of hardware on the chassis
4) The circuit layout, with all components and wiring]]> http://www.ampmaker.com/infocentre/thread-115.html Mon, 13 May 2013 14:48:02 -0500 http://www.ampmaker.com/infocentre/thread-115.html http://www.ampmaker.com/infocentre/thread-114.html Wed, 01 May 2013 05:46:13 -0500 http://www.ampmaker.com/infocentre/thread-114.html http://www.ampmaker.com home page, I am revising most of the Amp Maker kits. I will use this thread to add details as I work through the changes to the Double Six.

To clarify the ordering situation: the original Double Six kit will continue to be available until the new version is ready. You can decide whether to buy now or wait for the new version.

The #1 update
I've decided to make the Double Six a super flexible amp building course. The idea is to build an amp that's easy to modify to alter the tone to your own taste and needs.

To start, the new version of the Double Six will come with a wide-ranging Tone Tweaking Kit, including alternative components and circuit ideas to try out. The current Double Six version is just one example; you can also build a Tweed Princeton, a Blackface Vibro Champ or a 12W version of the SE-5a. And that's just for starters. ]]> http://www.ampmaker.com home page, I am revising most of the Amp Maker kits. I will use this thread to add details as I work through the changes to the Double Six.

To clarify the ordering situation: the original Double Six kit will continue to be available until the new version is ready. You can decide whether to buy now or wait for the new version.

The #1 update
I've decided to make the Double Six a super flexible amp building course. The idea is to build an amp that's easy to modify to alter the tone to your own taste and needs.

To start, the new version of the Double Six will come with a wide-ranging Tone Tweaking Kit, including alternative components and circuit ideas to try out. The current Double Six version is just one example; you can also build a Tweed Princeton, a Blackface Vibro Champ or a 12W version of the SE-5a. And that's just for starters. ]]> http://www.ampmaker.com/infocentre/thread-113.html Wed, 01 May 2013 05:14:40 -0500 http://www.ampmaker.com/infocentre/thread-113.html http://www.ampmaker.com home page, I am revising most of the Amp Maker kits. I will use this thread to add details as I work through the changes to the PP-36.

To clarify the ordering situation: the original PP-36 kit will continue to be available until the new version is ready. After that the original PP-36 will be available as a special order. You can decide whether to buy now or wait for the new version.

The #1 update
The new version of the PP-36 will have a wider tonal palette, thanks to the use of two EL84s and two 6L6s in the power amp section. You will be able to use them alone or blend them together. The prototype is up and running but needs tweaking - details to follow as soon as possible.]]> http://www.ampmaker.com home page, I am revising most of the Amp Maker kits. I will use this thread to add details as I work through the changes to the PP-36.

To clarify the ordering situation: the original PP-36 kit will continue to be available until the new version is ready. After that the original PP-36 will be available as a special order. You can decide whether to buy now or wait for the new version.

The #1 update
The new version of the PP-36 will have a wider tonal palette, thanks to the use of two EL84s and two 6L6s in the power amp section. You will be able to use them alone or blend them together. The prototype is up and running but needs tweaking - details to follow as soon as possible.]]> http://www.ampmaker.com/infocentre/thread-112.html Wed, 01 May 2013 04:54:57 -0500 http://www.ampmaker.com/infocentre/thread-112.html
To clarify the ordering situation: the original PP-18 (as used in the current sound clips and shown on many customer's clips on http://www.youtube.com) will be available to buy until the new version is released. So you can decide whether to buy now or wait for the new version.

The #1 update
The new version of the PP-18 will have VVR built-in as standard. VVR is a means of lowering the power supply voltages within the amp so that you can get the full distortion capability of the amplifier at lower room volumes. At the moment, I sell VVR kits as a separate item, but this will be integrated into the PP-18 circuit and build guide.

This single change makes the amp much more useful, but there will be more details posted here over the coming weeks.]]>
To clarify the ordering situation: the original PP-18 (as used in the current sound clips and shown on many customer's clips on http://www.youtube.com) will be available to buy until the new version is released. So you can decide whether to buy now or wait for the new version.

The #1 update
The new version of the PP-18 will have VVR built-in as standard. VVR is a means of lowering the power supply voltages within the amp so that you can get the full distortion capability of the amplifier at lower room volumes. At the moment, I sell VVR kits as a separate item, but this will be integrated into the PP-18 circuit and build guide.

This single change makes the amp much more useful, but there will be more details posted here over the coming weeks.]]> http://www.ampmaker.com/infocentre/thread-111.html Wed, 01 May 2013 04:46:56 -0500 http://www.ampmaker.com/infocentre/thread-111.html http://www.ampmaker.com home page, I am revising most of the Amp Maker kits. I will use this thread to add details as I work through the changes to the SE-5a.

To clarify the ordering situation: the original SE-5a (as used in the current sound clips and shown on many customer's clips on http://www.youtube.com) will be available to buy until the new version is released. So you can decide whether to buy now or wait for the new version.

The #1 update
The new version of the SE-5a will have VVR built-in as standard. VVR is a means of lowering the power supply voltages within the amp so that you can get the full distortion capability of the amplifier at lower room volumes. At the moment, I sell VVR kits as a separate item, but this will be integrated into the SE-5a circuit and build guide.

This single change makes the amp much more useful, but there will be more details posted here over the coming weeks.]]> http://www.ampmaker.com home page, I am revising most of the Amp Maker kits. I will use this thread to add details as I work through the changes to the SE-5a.

To clarify the ordering situation: the original SE-5a (as used in the current sound clips and shown on many customer's clips on http://www.youtube.com) will be available to buy until the new version is released. So you can decide whether to buy now or wait for the new version.

The #1 update
The new version of the SE-5a will have VVR built-in as standard. VVR is a means of lowering the power supply voltages within the amp so that you can get the full distortion capability of the amplifier at lower room volumes. At the moment, I sell VVR kits as a separate item, but this will be integrated into the SE-5a circuit and build guide.

This single change makes the amp much more useful, but there will be more details posted here over the coming weeks.]]> http://www.ampmaker.com/infocentre/thread-109.html Fri, 09 Dec 2011 04:56:46 -0600 http://www.ampmaker.com/infocentre/thread-109.html
Just like the Alembic F-2B, the Blackface 2-channel preamp (BF-2p) is a 1U rackmounting preamp designed to drive a separate poweramp. The Alembic unit came out in the '70s and has featured in the racks of many big-name bassists and guitarists, including David Gilmour and Peter Hook.

You can see information on the Alembic here: http://alembic.com/prod/f2b.html

The main difference between the F-2B and Amp Maker's BF-2p is that the BF-2p is entirely handwired (the F-2B uses a PCB). I chose this route to make it an easier build and to make it easier to modify.

I'll add more info and pix on the BF-2 here as soon as possible. For now, here's a simple shot of the preamp board (there are two in each BF-2p).

Expected release: February 2012

  preamp pic2.jpg (Size: 34.08 KB / Downloads: 1695) ]]>
Just like the Alembic F-2B, the Blackface 2-channel preamp (BF-2p) is a 1U rackmounting preamp designed to drive a separate poweramp. The Alembic unit came out in the '70s and has featured in the racks of many big-name bassists and guitarists, including David Gilmour and Peter Hook.

You can see information on the Alembic here: http://alembic.com/prod/f2b.html

The main difference between the F-2B and Amp Maker's BF-2p is that the BF-2p is entirely handwired (the F-2B uses a PCB). I chose this route to make it an easier build and to make it easier to modify.

I'll add more info and pix on the BF-2 here as soon as possible. For now, here's a simple shot of the preamp board (there are two in each BF-2p).

Expected release: February 2012

  preamp pic2.jpg (Size: 34.08 KB / Downloads: 1695) ]]> http://www.ampmaker.com/infocentre/thread-108.html Tue, 29 Nov 2011 15:32:39 -0600 http://www.ampmaker.com/infocentre/thread-108.html
The reason is that I get many more troubleshooting calls and emails for the SL-18. Whereas perhaps 1 in 20 customers for the other amp kits might need some post-sales support, for the SL-18 it's perhaps 1 in 5. Typically, the problem is extraneous noise or hum. It's sometimes quite hard to pin down - especially at a distance.

So I've discontinued the SL-18 as an official Amp Maker kit (see below for more on that) and I will spend the time that I would have spent on SL-18 support in developing another amp kit.]]>
The reason is that I get many more troubleshooting calls and emails for the SL-18. Whereas perhaps 1 in 20 customers for the other amp kits might need some post-sales support, for the SL-18 it's perhaps 1 in 5. Typically, the problem is extraneous noise or hum. It's sometimes quite hard to pin down - especially at a distance.

So I've discontinued the SL-18 as an official Amp Maker kit (see below for more on that) and I will spend the time that I would have spent on SL-18 support in developing another amp kit.]]> http://www.ampmaker.com/infocentre/thread-107.html Tue, 29 Nov 2011 10:37:53 -0600 http://www.ampmaker.com/infocentre/thread-107.html http://www.ampmaker.com/store/Punched-ch...5x9.html).

So they're perfect for typical 5-20W projects using 9-pin valves.

There's one minor issue: the 22mm holes that were punched for the 9-pin sockets is just too tight for the ceramic 9-pin valve sockets that I carry, which need a 22.5mm hole. (One of those annoying changes of spec that some manufacturers do without letting anyone know.)

There are two solutions:
1) do a little extra metalwork yourself to widen the holes to 22.5mm
2) I have some alternative sockets that will fit in the holes (not shown in the Webshop, because ordered them specifically for this chassis). So if you want sockets, we can add them to the order manually.

Price: £20

(photo to come)]]> http://www.ampmaker.com/store/Punched-ch...5x9.html).

So they're perfect for typical 5-20W projects using 9-pin valves.

There's one minor issue: the 22mm holes that were punched for the 9-pin sockets is just too tight for the ceramic 9-pin valve sockets that I carry, which need a 22.5mm hole. (One of those annoying changes of spec that some manufacturers do without letting anyone know.)

There are two solutions:
1) do a little extra metalwork yourself to widen the holes to 22.5mm
2) I have some alternative sockets that will fit in the holes (not shown in the Webshop, because ordered them specifically for this chassis). So if you want sockets, we can add them to the order manually.

Price: £20

(photo to come)]]> http://www.ampmaker.com/infocentre/thread-106.html Tue, 29 Nov 2011 10:26:55 -0600 http://www.ampmaker.com/infocentre/thread-106.html
They vary in size, from about 10x50mm through to 200x50mm (all are rectangular). They're perfect for short tag strips, power supply boards, heater DC boards, hand-wired VVR boards, etc.

Price: 4p per square centimetre (approx 3/8in by 3/8in)

Not quite sure how to add these to the shop at the moment, so email with your approximate size requirement and I'll find the closest I've got.

(photo to come)]]>
They vary in size, from about 10x50mm through to 200x50mm (all are rectangular). They're perfect for short tag strips, power supply boards, heater DC boards, hand-wired VVR boards, etc.

Price: 4p per square centimetre (approx 3/8in by 3/8in)

Not quite sure how to add these to the shop at the moment, so email with your approximate size requirement and I'll find the closest I've got.

(photo to come)]]> http://www.ampmaker.com/infocentre/thread-105.html Sun, 13 Nov 2011 09:48:56 -0600 http://www.ampmaker.com/infocentre/thread-105.html Changing to a Fender Blackface tone stack
The Double Six has fully independent tone controls. But the turret board was designed with lots of flexibility, and you can switch to a Fender tone stack if you want to experiment.

It's slightly less lossy (so there's a little more gain on tap before you use the Boost switch). Once the change is made you have effectively the same circuit as Fender's Blackface Champ. Of course, you still keep the Double Six's power amp, so it's luoder and more flexible.

To start with, your Double Six will look like this. The changes you'll be making include the front panel controls and about a dozen components on the turret board.

]]> Changing to a Fender Blackface tone stack
The Double Six has fully independent tone controls. But the turret board was designed with lots of flexibility, and you can switch to a Fender tone stack if you want to experiment.

It's slightly less lossy (so there's a little more gain on tap before you use the Boost switch). Once the change is made you have effectively the same circuit as Fender's Blackface Champ. Of course, you still keep the Double Six's power amp, so it's luoder and more flexible.

To start with, your Double Six will look like this. The changes you'll be making include the front panel controls and about a dozen components on the turret board.

]]> http://www.ampmaker.com/infocentre/thread-104.html Fri, 11 Nov 2011 10:29:48 -0600 http://www.ampmaker.com/infocentre/thread-104.html Adding a tone control
The Tweed Champ circuit is as simple as it gets: two valves set up to provide moderate amounts of gain and one knob to control Volume. It's a fairly simple modification to add a Tone control - Fender did it and called the result the Tweed Princeton (5F2 and 5F2-A models). You can do the same to the WF-55, and here's how.

You will need:
* 1M log pot
* knob for the pot
* 4.7nF capacitor (typically Orange Drop)
* 470pF capacitor (typically silver mica)
* 22uf/25V capacitor (typically electrolytic)
* some extra wire

Most of these components will be mounted directly on the front panel next to the Volume control. Before you start, the Volume pot and its wiring look like this:

]]> Adding a tone control
The Tweed Champ circuit is as simple as it gets: two valves set up to provide moderate amounts of gain and one knob to control Volume. It's a fairly simple modification to add a Tone control - Fender did it and called the result the Tweed Princeton (5F2 and 5F2-A models). You can do the same to the WF-55, and here's how.

You will need:
* 1M log pot
* knob for the pot
* 4.7nF capacitor (typically Orange Drop)
* 470pF capacitor (typically silver mica)
* 22uf/25V capacitor (typically electrolytic)
* some extra wire

Most of these components will be mounted directly on the front panel next to the Volume control. Before you start, the Volume pot and its wiring look like this:

]]> http://www.ampmaker.com/infocentre/thread-103.html Thu, 10 Nov 2011 10:22:51 -0600 http://www.ampmaker.com/infocentre/thread-103.html Using the Line out
At any time when you have an amplifier and speaker connected to the Box of Matches, you can use the Line out to connect to another audio device. For example:

1) connect to the input of another guitar amplifier. It will work as a slave - you get all of the tone of the first amplifier, and you can shape it further and add more distortion and EQ through the second amp.

2) connect to a computer or recording device. You will capture a tone that includes all of your guitar plus amplifier tone. For clean tones, this may be perfect for recording directly as-is. For distorted tones, you will probably want to emulate the EQ* that a guitar cabinet normally adds - perhaps with a software cabinet impulse/simulator.

3) connect to a PA system. As above, you might want to add EQ for use with a distorted guitar tone*.

* It's a historical accident that a guitar cabinet has a very limited bandwidth - it typically 'throws away' most of the frequencies over 6kHz or so. Your ear is used to this heavily EQed guitar tone - especially with distorted guitar tone packed with high frequency harmonics. So, if you record without a speaker cabinet or some emulation of it, distorted guitar can sound very 'fizzy.']]> Using the Line out
At any time when you have an amplifier and speaker connected to the Box of Matches, you can use the Line out to connect to another audio device. For example:

1) connect to the input of another guitar amplifier. It will work as a slave - you get all of the tone of the first amplifier, and you can shape it further and add more distortion and EQ through the second amp.

2) connect to a computer or recording device. You will capture a tone that includes all of your guitar plus amplifier tone. For clean tones, this may be perfect for recording directly as-is. For distorted tones, you will probably want to emulate the EQ* that a guitar cabinet normally adds - perhaps with a software cabinet impulse/simulator.

3) connect to a PA system. As above, you might want to add EQ for use with a distorted guitar tone*.

* It's a historical accident that a guitar cabinet has a very limited bandwidth - it typically 'throws away' most of the frequencies over 6kHz or so. Your ear is used to this heavily EQed guitar tone - especially with distorted guitar tone packed with high frequency harmonics. So, if you record without a speaker cabinet or some emulation of it, distorted guitar can sound very 'fizzy.']]> http://www.ampmaker.com/infocentre/thread-102.html Thu, 10 Nov 2011 10:09:23 -0600 http://www.ampmaker.com/infocentre/thread-102.html Simple impedance matching
For the simplest job of matching a valve amplifier to a speaker cabinet with a different impedance, it couldn't be easier:
* use a speaker cable to run from the amplifier's speaker out socket to the matching socket on the back panel of the Box of Matches
* you can use either the top or bottom socket (they are joined internally so it does not make a difference)
* use another speaker cable to run from your cabinet to the matching socket on the back panel of the Box of Matches
* again, you can use either socket

That's it! The Box of Matches' transformer will do the conversion necessary to match the speaker cabinet to the amplifier.

Remember not to exceed the BM30 model's 30W power rating.]]> Simple impedance matching
For the simplest job of matching a valve amplifier to a speaker cabinet with a different impedance, it couldn't be easier:
* use a speaker cable to run from the amplifier's speaker out socket to the matching socket on the back panel of the Box of Matches
* you can use either the top or bottom socket (they are joined internally so it does not make a difference)
* use another speaker cable to run from your cabinet to the matching socket on the back panel of the Box of Matches
* again, you can use either socket

That's it! The Box of Matches' transformer will do the conversion necessary to match the speaker cabinet to the amplifier.

Remember not to exceed the BM30 model's 30W power rating.]]> http://www.ampmaker.com/infocentre/thread-101.html Fri, 04 Nov 2011 13:17:32 -0500 http://www.ampmaker.com/infocentre/thread-101.html
The short answer:
Yes, but it’s not trivial, and it’s difficult to get it sounding good.

The long and detailed answer:
The main reason for having an FX loop in an amplifier is to add time-domain effects, such as delay, chorus and/or reverb. However, all of these sound best when placed AFTER compression and distortion. If you look at the typical FX chain in a multi-FX pedal, guitarist's pedal-board, digital modeller or backline+PA rig, you will almost always find that these are the last effects applied. The reason is that it sounds natural and musical.

If time doman FX are applied to a signal BEFORE distortion and/or compression, the result is messy. The compression 'interferes' with the delayed element: echo repeats and reverb tails get increased in volume in relation to the dry guitar signal. So instead of the echoes/reverb being able to tail off naturally (as they do when played through a clean amplifier), the repeats/decay get boosted, and it can sound boomy. It becomes hard to mix in with the dry signal without smearing the dry signal. Typically, to solve this problem, you find yourself reducing the amount of reverb and/or distortion levels to try to stop this mess from ruining the dry signal.

What has this got to do with the WF-55, SE-5a, PP-18, SL-18, PP-36, etc? Well, all of these amplifiers are designed with power valve distortion as a significant part of the amp’s overall distortion tone. So, if you were to place an FX loop within the amplifier’s preamp signal path, you get the problem mentioned above - the power valve distortion and compression messes with the natural sound of the chorus/echo/reverb. This is true of many vintage-style amplifier circuits, too: Tweed Deluxe, Vox AC-30, JTM45, etc.

So why not keep the power amp clean?
That’s usually the best approach, but – of course – you lose the power valve’s contribution to your overdrive and distortion tone. In most vintage-style amplifiers you end up with a very clean amplifier tone, because there’s little distortion in the preamp circuit itself. It’s no coincidence that the best sounding vintage reverb amplifiers are like this: the Fender Blackface and Silverface models, such as the Super Reverb and Twin Reverb.

To get good amounts of distortion and a good-sounding FX loop in an amplifier circuit, you need:
1) a preamp circuit that can provide plenty of distortion, running into...
2) the FX loop circuit, running into...
3) a clean power amp.

There are plenty of commercial examples: Soldano SLO, Diezel VH4, most modern Marshalls and many Mesa Boogies. But these all sound and respond differently when compared with an amplifier that uses lots of power valve distortion. It’s also quite a bit more expensive and significantly more complicated to build as a project.

Back to the Amp Maker amplifiers: we’d be adding at least two extra valves:
a) to achieve the same sort of distortion levels in the preamp alone
b) to drive the FX loop
c) to recover FX unit's output signal back up to a decent level
d) all to mix it back in with the dry signal
e) to drive the output valve(s) which we'd now run totally clean

That’s such a big change that it’s better to start with a clean sheet of paper (IMHO!). Which I will do.]]>
The short answer:
Yes, but it’s not trivial, and it’s difficult to get it sounding good.

The long and detailed answer:
The main reason for having an FX loop in an amplifier is to add time-domain effects, such as delay, chorus and/or reverb. However, all of these sound best when placed AFTER compression and distortion. If you look at the typical FX chain in a multi-FX pedal, guitarist's pedal-board, digital modeller or backline+PA rig, you will almost always find that these are the last effects applied. The reason is that it sounds natural and musical.

If time doman FX are applied to a signal BEFORE distortion and/or compression, the result is messy. The compression 'interferes' with the delayed element: echo repeats and reverb tails get increased in volume in relation to the dry guitar signal. So instead of the echoes/reverb being able to tail off naturally (as they do when played through a clean amplifier), the repeats/decay get boosted, and it can sound boomy. It becomes hard to mix in with the dry signal without smearing the dry signal. Typically, to solve this problem, you find yourself reducing the amount of reverb and/or distortion levels to try to stop this mess from ruining the dry signal.

What has this got to do with the WF-55, SE-5a, PP-18, SL-18, PP-36, etc? Well, all of these amplifiers are designed with power valve distortion as a significant part of the amp’s overall distortion tone. So, if you were to place an FX loop within the amplifier’s preamp signal path, you get the problem mentioned above - the power valve distortion and compression messes with the natural sound of the chorus/echo/reverb. This is true of many vintage-style amplifier circuits, too: Tweed Deluxe, Vox AC-30, JTM45, etc.

So why not keep the power amp clean?
That’s usually the best approach, but – of course – you lose the power valve’s contribution to your overdrive and distortion tone. In most vintage-style amplifiers you end up with a very clean amplifier tone, because there’s little distortion in the preamp circuit itself. It’s no coincidence that the best sounding vintage reverb amplifiers are like this: the Fender Blackface and Silverface models, such as the Super Reverb and Twin Reverb.

To get good amounts of distortion and a good-sounding FX loop in an amplifier circuit, you need:
1) a preamp circuit that can provide plenty of distortion, running into...
2) the FX loop circuit, running into...
3) a clean power amp.

There are plenty of commercial examples: Soldano SLO, Diezel VH4, most modern Marshalls and many Mesa Boogies. But these all sound and respond differently when compared with an amplifier that uses lots of power valve distortion. It’s also quite a bit more expensive and significantly more complicated to build as a project.

Back to the Amp Maker amplifiers: we’d be adding at least two extra valves:
a) to achieve the same sort of distortion levels in the preamp alone
b) to drive the FX loop
c) to recover FX unit's output signal back up to a decent level
d) all to mix it back in with the dry signal
e) to drive the output valve(s) which we'd now run totally clean

That’s such a big change that it’s better to start with a clean sheet of paper (IMHO!). Which I will do.]]> http://www.ampmaker.com/infocentre/thread-100.html Fri, 04 Nov 2011 10:39:32 -0500 http://www.ampmaker.com/infocentre/thread-100.html
1) Short answer: Celestion G12H 30W for british/overdriven tones. JBL E120 for cleaner tones. This is entirely my own subjective preference; you may hate them!

2) Longer answer: The speaker and its cabinet is a very significant factor in the sound of any guitar amp. Guitar speakers and cabinets don't have a flat frequency response; and all of them can accentuate or suppress certain parts of the audio spectrum.

For example, I find the G12M 25W 'Greenback' to be quite mid-focused, and quite 'nasal' in an open-back combo cabinet. I think that suits the classic 'British invasion' tone of the mid-to-late '60s. But if I dial in a later '70s hard rock tone with the amp, the same cabinet doesn't sound right to my ears. And I end up back with the G12H 30W cabinet that I mentioned above.

It is 100% subjective though, and what I don't like might be your tonal 'sweetspot.' I've never got on with 10-inch speakers, for instance, whereas some guys just love them.

Think about this... it's no coincidence that the speaker is every bit as important in shaping YOUR own tone as the other wire+magnet you use - right at the other end of the signal path is your guitar pickup. Some guys love the articulation of their noisy single coils, others prefer the thicker tone of humbuckers. And I would never presume to tell a guitarist which pickups to use for his tone!

If you're choosing a speaker for your amp kit, and really don't know where to start, my recommendation is to start with a speaker that already works for you.

For me, it's a '70s Marshall 4x12 with G12H 30W speakers. I experiment a lot, but I always seem to come back to this - it's become my reference cabinet for every kit I build and every amp I own.]]>
1) Short answer: Celestion G12H 30W for british/overdriven tones. JBL E120 for cleaner tones. This is entirely my own subjective preference; you may hate them!

2) Longer answer: The speaker and its cabinet is a very significant factor in the sound of any guitar amp. Guitar speakers and cabinets don't have a flat frequency response; and all of them can accentuate or suppress certain parts of the audio spectrum.

For example, I find the G12M 25W 'Greenback' to be quite mid-focused, and quite 'nasal' in an open-back combo cabinet. I think that suits the classic 'British invasion' tone of the mid-to-late '60s. But if I dial in a later '70s hard rock tone with the amp, the same cabinet doesn't sound right to my ears. And I end up back with the G12H 30W cabinet that I mentioned above.

It is 100% subjective though, and what I don't like might be your tonal 'sweetspot.' I've never got on with 10-inch speakers, for instance, whereas some guys just love them.

Think about this... it's no coincidence that the speaker is every bit as important in shaping YOUR own tone as the other wire+magnet you use - right at the other end of the signal path is your guitar pickup. Some guys love the articulation of their noisy single coils, others prefer the thicker tone of humbuckers. And I would never presume to tell a guitarist which pickups to use for his tone!

If you're choosing a speaker for your amp kit, and really don't know where to start, my recommendation is to start with a speaker that already works for you.

For me, it's a '70s Marshall 4x12 with G12H 30W speakers. I experiment a lot, but I always seem to come back to this - it's become my reference cabinet for every kit I build and every amp I own.]]> http://www.ampmaker.com/infocentre/thread-99.html Wed, 02 Nov 2011 12:22:38 -0500 http://www.ampmaker.com/infocentre/thread-99.html First power up
With the ground connections tested, it’s time to power up your amplifier. There are some important tests to do before plugging a guitar in, however. Before you start, print out the Test point diagram and Double Six voltage chart.





When you have a pen and multimeter ready, prepare your amplifier for the tests:

• Unplug the guitar lead from the amp’s Input socket

• Plug a speaker cable and cabinet into one of the speaker sockets

• Turn Watts control to 1

• Make sure there are NO VALVES installed

• Remove jewellery/etc that might dangle into the amplifier chassis

• Plug the mains cable into wall socket

• Switch Power switch on, keeping your fingers, multimeter probes, etc outside the chassis

The red neon light should start to glow and you may hear a low level acoustic hum from the power transformer mounted on the chassis. This is normal. You may also hear a very low-level hum from your speaker – this is electro-magnetically coupled hum directly between the two transformers and is also normal. If you hear a loud hum or buzz switch off immediately and contact Amp Maker.]]> First power up
With the ground connections tested, it’s time to power up your amplifier. There are some important tests to do before plugging a guitar in, however. Before you start, print out the Test point diagram and Double Six voltage chart.





When you have a pen and multimeter ready, prepare your amplifier for the tests:

• Unplug the guitar lead from the amp’s Input socket

• Plug a speaker cable and cabinet into one of the speaker sockets

• Turn Watts control to 1

• Make sure there are NO VALVES installed

• Remove jewellery/etc that might dangle into the amplifier chassis

• Plug the mains cable into wall socket

• Switch Power switch on, keeping your fingers, multimeter probes, etc outside the chassis

The red neon light should start to glow and you may hear a low level acoustic hum from the power transformer mounted on the chassis. This is normal. You may also hear a very low-level hum from your speaker – this is electro-magnetically coupled hum directly between the two transformers and is also normal. If you hear a loud hum or buzz switch off immediately and contact Amp Maker.]]> http://www.ampmaker.com/infocentre/thread-98.html Wed, 02 Nov 2011 12:19:41 -0500 http://www.ampmaker.com/infocentre/thread-98.html Check your circuit
Before you power up, it’s well worth checking your circuit. These tests take a just a few minutes and are essential. First, do a visual check of your amplifier against the final layout diagram here:
* http://www.ampmaker.com/images/ak02kit/ak02cw24.jpg

Work methodically through the diagram and check each and every wire and connection. When that’s done – and any mistakes are rectified – then you can do some simply continuity checks. These will ensure that the most important connections are good, helping to identify bad solder joints, missing connections, etc.

• Plug a guitar cable (but without guitar) into the Input

• Plug a speaker cable (but without speaker cabinet) into any of the outputs

• Plug a mains (IEC) lead into the amplifier BUT DO NOT PLUG THE OTHER END INTO THE MAINS SOCKET (because at this stage, we’re just checking connections, and we don’t want any voltage inside the amplifier)

• Set all 4 pots to midway (any position for the Watts switch, S3 is OK)

• Set the Fat and Boost switches in the up position (i.e. off)

Now use your multimeter to check for continuity (or for a resistance reading of under 1 ohm if your multimeter does not have a continuity checker) for each of the following:

• Between the Earth (or ground) pin of your mains plug and the shield of the plug at the end of the guitar cable

• Between the Earth (or ground) pin of your mains plug and the shield of the plug at the end of the speaker cable

• Between the Earth (or ground) pin of your mains plug and the three M3 grounding lugs that are located on the turret board

If you read anything other than good continuity for any of these tests, go back and check your wiring. Contact Amp Maker if you cannot locate the problem. Your amp is NOT safe to switch on until this is fixed.]]> Check your circuit
Before you power up, it’s well worth checking your circuit. These tests take a just a few minutes and are essential. First, do a visual check of your amplifier against the final layout diagram here:
* http://www.ampmaker.com/images/ak02kit/ak02cw24.jpg

Work methodically through the diagram and check each and every wire and connection. When that’s done – and any mistakes are rectified – then you can do some simply continuity checks. These will ensure that the most important connections are good, helping to identify bad solder joints, missing connections, etc.

• Plug a guitar cable (but without guitar) into the Input

• Plug a speaker cable (but without speaker cabinet) into any of the outputs

• Plug a mains (IEC) lead into the amplifier BUT DO NOT PLUG THE OTHER END INTO THE MAINS SOCKET (because at this stage, we’re just checking connections, and we don’t want any voltage inside the amplifier)

• Set all 4 pots to midway (any position for the Watts switch, S3 is OK)

• Set the Fat and Boost switches in the up position (i.e. off)

Now use your multimeter to check for continuity (or for a resistance reading of under 1 ohm if your multimeter does not have a continuity checker) for each of the following:

• Between the Earth (or ground) pin of your mains plug and the shield of the plug at the end of the guitar cable

• Between the Earth (or ground) pin of your mains plug and the shield of the plug at the end of the speaker cable

• Between the Earth (or ground) pin of your mains plug and the three M3 grounding lugs that are located on the turret board

If you read anything other than good continuity for any of these tests, go back and check your wiring. Contact Amp Maker if you cannot locate the problem. Your amp is NOT safe to switch on until this is fixed.]]> http://www.ampmaker.com/infocentre/thread-97.html Wed, 02 Nov 2011 12:15:40 -0500 http://www.ampmaker.com/infocentre/thread-97.html Output transformer wiring
There are two bundles of wire to solder to the output transformer:

• red and brown wires to the primary winding

• orange, yellow, green and grey wires for the secondary winding

Solder these wires as shown in the diagram here. Three of the solder lugs on the primary winding are unused; this is normal.




As with the power transformer, there is a touch-proof cover to add. (It’s to protect people working on a powered-up amplifier from accidentally touching one of the primary winding’s high-voltage lugs.) To use this cover:

• solder the wires to the transformer lugs (as detailed above)

• then thread the wires through the holes in the touch-proof cover

• slide the cover into position over the solder lugs

Then, twist the two bundles of wire together and thread them through the rubber grommet and the corresponding hole in the turret board. The red and brown pair connects to a pair of turrets close to this turret board hole. Trim and solder these two wires as shown here.



(For clarity, the diagram shows the rest of the amplifier greyed out so that the output transformer wire bundles are easily seen.)]]> Output transformer wiring
There are two bundles of wire to solder to the output transformer:

• red and brown wires to the primary winding

• orange, yellow, green and grey wires for the secondary winding

Solder these wires as shown in the diagram here. Three of the solder lugs on the primary winding are unused; this is normal.




As with the power transformer, there is a touch-proof cover to add. (It’s to protect people working on a powered-up amplifier from accidentally touching one of the primary winding’s high-voltage lugs.) To use this cover:

• solder the wires to the transformer lugs (as detailed above)

• then thread the wires through the holes in the touch-proof cover

• slide the cover into position over the solder lugs

Then, twist the two bundles of wire together and thread them through the rubber grommet and the corresponding hole in the turret board. The red and brown pair connects to a pair of turrets close to this turret board hole. Trim and solder these two wires as shown here.



(For clarity, the diagram shows the rest of the amplifier greyed out so that the output transformer wire bundles are easily seen.)]]> http://www.ampmaker.com/infocentre/thread-96.html Wed, 02 Nov 2011 11:55:14 -0500 http://www.ampmaker.com/infocentre/thread-96.html


Now do the same for V2 and V3. In each case, there’s just one yellow wire to connect to the turret board. At the valve socket end of this wire, strip a little extra wire and run it through pin 1 to pin 8, and solder both pins. (Note: for V2 and V3, pin 6 has no connection.)



Trim and solder the short black wire (the one left over from the power transformer's heater supply) to the grounding lug at the top right of the turret board.

]]>


Now do the same for V2 and V3. In each case, there’s just one yellow wire to connect to the turret board. At the valve socket end of this wire, strip a little extra wire and run it through pin 1 to pin 8, and solder both pins. (Note: for V2 and V3, pin 6 has no connection.)



Trim and solder the short black wire (the one left over from the power transformer's heater supply) to the grounding lug at the top right of the turret board.

]]>