Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Texson on April 24, 2026, 12:36:50 am

Title: AO-35 Schematics
Post by: Texson on April 24, 2026, 12:36:50 am

Does anyone know where I can find a list of schematics for the various ao-35 conversions? I'm not sure which conversion I want but would like to check out a few schems while I am deciding.

Title: Re: AO-35 Schematics
Post by: sluckey on April 24, 2026, 07:16:59 am

I doubt you will directly find such a list. Google is your friend. Spend a day surfing google and you can put together an extensive list. Most of the conversions will be based on the Vox AC-15 and Marshall 1974 18 watt.

Lots of Hammond conversions (including AO-35) here...

     https://ampgarage.com/forum/viewtopic.php?f=6&t=24331

Title: Re: AO-35 Schematics
Post by: Texson on April 27, 2026, 12:45:31 am

Thanks. That's way more than I had.

Title: Re: AO-35 Schematics
Post by: bmccowan on April 28, 2026, 08:55:51 am

As Steve said, Google is your friend, or another search engine if you are anti-Google. You also might try Claude if you are not anti-AI. Everybody is anti-something these days.
Some thoughts about the AO-35. Dr. Z made the original Carmen Ghia from AO-35s. Clones and semi-clone schematics can be found under Charming Ghia and Phoenix Project and other.
Richard Goodsell also based his Goodsell 17 on the AO-35. I have searched for a schematic, without luck, for that amp. Owners love that amp. I have read that the power amp was kept and the preamp is based on the Fender 5F6a. Richard closed his business a while back and has been promising to start a DIY website or YouTube channel as he gets many info requests.
Another amp easily made from AO-35 bones is the Matchless Spitfire.
After toying with converting AO-35s, retaining the original chassis and board. I said F-it and robbed the iron and a few other parts for projects. The chassis and board were too crowded for my old eyes and arthritic fingers. I could get the amps to work but they were always too noisy. The AO-39 is easier to work with.
I have not searched for AO-35 based schematics in a few years, so if you find some interesting stuff - please share.

Title: Re: AO-35 Schematics
Post by: mresistor on April 28, 2026, 04:59:28 pm

Here's the original Hammond AO-35 schematic

Title: Re: AO-35 Schematics
Post by: kagliostro on April 29, 2026, 01:54:22 am

Quote

Google is your friend

One time ago, now ChatGPT

Franco

Title: Re: AO-35 Schematics
Post by: Lectroid on April 30, 2026, 09:44:27 am

This is my take on an AO-35 chassis, (with a lot of help from tubenit and many others.) The 1-tube reverb is not deep enough for surf music but enough for anything else.  I used the Hammond PT and OT, but the tone stack is from the Fender blackface.   The preamp distorts smoothly from about 4 on the Volume, with all the overdrive you need unless you're into metal.  A great little amp for rock/blues, easily pushes a 35W Jensen.

Title: Re: AO-35 Schematics
Post by: dude on May 03, 2026, 10:18:24 am

Quote from: Lectroid on April 30, 2026, 09:44:27 am

This is my take on an AO-35 chassis, (with a lot of help from tubenit and many others.) The 1-tube reverb is not deep enough for surf music but enough for anything else.  I used the Hammond PT and OT, but the tone stack is from the Fender blackface.   The preamp distorts smoothly from about 4 on the Volume, with all the overdrive you need unless you're into metal.  A great little amp for rock/blues, easily pushes a 35W Jensen.

Has this Reverb amp been built and proven..?