My Allen Accomplice build

[stormbringer]

In Aug-2010, I built an Allen Accomplice, which is based on a BF Fender Deluxe. It was great fun to build, and David Allen was friendly, prompt and helpful over email. Here are some photos:

[loudthud]

Nice looking amp! Do you have any pictures of the top of the chassis with the transformers? How do you like the features of the amp?

[stormbringer]

Thanks loudthud. I like this amp alot. It is based on a BF Deluxe, but with only one channel and no tremolo. Here are some of the cool features:

- It is really quiet. That's not a feature, but it makes everything else work better...
- Great reverb, with reverb tone control.
- MV that works well
- RAW pot that takes out the tone circuit. With the RAW on 10, the tone circuit is bypassed to give a lot more mids and a lot more gain. I usually set the RAW on 2.
- takes 6V6s or 6L6s. Mine has JJ 6V6s in it at the moment
- external bias jacks and pot.

I will probably try adding the following at some point:
- push-pull pot to switch the cathode bypass cap(s). I have one such three-way toggle on another amp that I use quite a bit, and Fargen has one that he calls a 'decade' switch on his mini plex.
- toying with the idea of replacing the reverb tone pot with a presence control.

I'll add some photos of the trannies and tubes shortly.

[tubeswell]

Nice faceplate. Is that screen-printed ally? or...?

[stormbringer]

Nice faceplate. Is that screen-printed ally? or...?

Good question. To be honest I don't remember the details since it came with the Allen kit. It looks pretty much like the BF fenders and had some adhesive on the backside. But I don't recall the material.

[stormbringer]

Here are some photos of the tube side of the chassis. One shows the tubes glowing, the other shows the preamp tubes shields. I have a blue pilot light in there now, but I bought nearly every colour lens available.

[scole]

could you show the schematic/layout?

[stormbringer]

I don't have an electronic version of the schematic, and I didn't find any online. Sorry. Let me know if you have any specific questions.

I suspect designers of tube amp kits probably don't want their designs shared online. I don't know how I feel about that...

[big_teee]

I don't have an electronic version of the schematic, and I didn't find any online. Sorry. Let me know if you have any specific questions.

I suspect designers of tube amp kits probably don't want their designs shared online. I don't know how I feel about that...

You paid the price, It's your decision whether to make it public.
Could you maybe compare it to some of the layouts on the weber site?
They show Schematics and Layouts, maybe there is something real similar.
Weber Amplifier Kits
Thanks,
Terry

[stormbringer]

You paid the price, It's your decision whether to make it public.
Could you maybe compare it to some of the layouts on the weber site?
They show Schematics and Layouts, maybe there is something real similar.
Weber Amplifier Kits
Thanks,
Terry

Hi Terry,
I"m not too familiar with the Weber kits at the moment (they have so many; I'll love through the list soon). The Accomplice is similar to the AB763 blackface Deluxe Reverb (schematics available everywhere). Some differences are:

- AA has 12AX7 for phase inverter and reverb driver, Deluxe uses 12AT7 for these
- AA has mid control and a 'raw' control in the tone stack. The latter takes out the tone stack.
- AA has only one input and one channel; no tremolo
- AA has external adjustable bias points and pot; don't know about deluxe

Other AA features:
- star ground near input
- can swap out 6V6 with 6L6
- can get two different OTs
- master volume

Cheers, John

[big_teee]

Thanks John:
I've been Looking over the Weber 6A14.
It has several versions.
A 6v6 or a 6l6 version.
They don't have the raw control.
Here's the 6V6 Version with the 10 inch speaker Combo or head.
http://taweber.powweb.com/store/6a14_layout.jpg
It looks a little like your amp.
I just built a Marshall Clone, may see if I can rassle a Weber with Tremelo and Reverb.
Later,
Terry

[stormbringer]

Thanks John:
I've been Looking over the Weber 6A14.
It has several versions.
A 6v6 or a 6l6 version.
They don't have the raw control.
Here's the 6V6 Version with the 10 inch speaker Combo or head.
http://taweber.powweb.com/store/6a14_layout.jpg
It looks a little like your amp.
I just built a Marshall Clone, may see if I can rassle a Weber with Tremelo and Reverb.
Later,
Terry

The 6A20 and 6A20HP look similar to the AA, but with a more typical two-channel layout. The Weber has Tremolo, whereas the AA does not. I didn't trace my way through the circuit, however, and I don't know how the parts compare. The Allen has a star ground scheme and is very quiet, which is important to me because I usually hit it with some OD pedals. I can't tell where the grounds go on the weber layouts.

[scole]

id like to know where the ground points are, and also how the master vol and raw control are wired.

[stormbringer]

id like to know where the ground points are, and also how the master vol and raw control are wired.

I found part of an Allen Encore layout online that shows the raw pot and the location of the main star ground near the input: http://www.el34world.com/Forum/index.php?topic=8303.0

My raw control is identical.

On the Encore and Accomplice, most signal grounds go directly to the star ground. The cathodes of V1a, V1b, and V2 are tied together and sent to star under the board (similar to rightmost ground wire on the partial encore layout). V3 cathodes are tied together and sent to star. MV ground goes to star. Two of the three 20 uF filter caps are sent to the star ground, while the other 20 uF filter cap is grounded on one of the PT bolts. The first filter cap (40 uF) is grounded on another one of the PT bolts.

I've added a higher-res version of one of the photos.

[big_teee]

[ATTACH=CONFIG]15397[/ATTACH]

I found part of an Allen Encore layout online that shows the raw pot and the location of the main star ground near the input: raw control wiring - Hoffman Ampifiers Guitar Tube amp forum

My raw control is identical.

On the Encore and Accomplice, most signal grounds go directly to the star ground. The cathodes of V1a, V1b, and V2 are tied together and sent to star under the board (similar to rightmost ground wire on the partial encore layout). V3 cathodes are tied together and sent to star. MV ground goes to star. Two of the three 20 uF filter caps are sent to the star ground, while the other 20 uF filter cap is grounded on one of the PT bolts. The first filter cap (40 uF) is grounded on another one of the PT bolts.

I've added a higher-res version of one of the photos.
[ATTACH=CONFIG]15397[/ATTACH]

Thanks Again for Going Above And Beyond the Call!
B_T