I built this AES AE-25 as a kit from the factory. And then I started making some major modifications. So, this "is" and "is not" a factory AE-25. Read on for details.
The first thing I did was replace the factory signal caps. I used 0.22uF Cardas caps to replace the factory KimberKaps.
Next up was adding some spare capacitance to the C- supply with the addition of a Panasonic electrolytic.
Third, I moved the power transformer off of the main chassis into a separate box. The connections are handled by a 12-pole Neutrik Speak-On connecter. This dramatically lowered the noise floor and tightened up the imaging relative to the original AE-25.
Fourth, I changed the inputs over to balanced only (the SE inputs on the rear apron no longer work). This is a little ugly as I never put in the effort to mount balanced input jacks on to the chassis. As you can see, the plugs hang out of a hole in the middle of the front apron (the right channel is denoted with the electrical tape!).
Last, and this was really the gem in all of my mods: I replaced the original B+ chokes with (dual-mono) solid-state voltage regulator circuit. This VR circuit is based on Welborne Labs PS-3 and uses a stack of zener diodes to set the regulated voltage. That is the big board in the picture. The effect of this on the sounds was jaw-dropping. This was not longer a factory AE-25 but something much better. Something different with tons of space between the instruments and an exceptionally low noise floor.
Oh yeah. At some point I replaced the down-stream B+ electrolytics with some big Solen polypros. Made the amp much faster and transients much cleaner.
The amp is currently wired up for triode but can be re-wired for ultra-linear. In triode, I think it produces 15W which probably means you need fairly efficient speakers (it drove my 87 dB's just fine).
There is no factory box. And the manual is not with it. But, I will look around in my boxes of books to find it as it has the schematic.
I'll include the matched quad of Valve Art KT100's and matched pairs of Sovtek 6922 and Ei 6FQ7s I have for it (and some other tubes that will work in it I have rattling around). All the tubes are used. I would probably replace all of the tubes as they were used for a couple of years and Class A amps tend to "use" tubes quickly.
This thing was a great project and it really sounds terrific. I'm not sure what else I could have done to the circuit without just throwing money at it. It will be securely shipped. I'm selling because it has been in storage for a couple of years and would remain there for the foreseeable future. Time to let someone else enjoy it.
Buyer to pay shipping. PayPal only.