Aum Aocustics OEM Guitar Amp Guitar (EF86, 12AX7, EL34 or genre tubes, Muallard GZ34 rectifier) 2026 - Black Anodized CNC 1/8" Chassis

A Guitar Amp Made By Aum Acoustics in Boston, MA - OEM (Custom) - Unused

My cost for this amplifier was well over $4,000. (For just the parts cost!) I’m selling it for $1,700, and I will pay the actual UPS Ground shipping cost from me to you and the Reverb processing fee. That’s it!

I’m already paying 8.19% to Reverb for the privilege of this ad. That’s $139.23 ($1,700 - $139.23 = $1,560.77 net). That’s lower than I was originally going to go, but it is what it is. And I’m paying for UPS Ground shipping cost from me to you.

You, on the other hand, will have the Reverb protection, the selling fee paid, the shipping cost covered, and the guitar shipped from me to you. So your price will be $1700.

I’ve purchased a shipping box and a 4 x 8 sheet of Styrofoam from Home Depot to ship this amp safely to you. That lowers my net even more, so please don’t ask if I can lower it further. I’ve already lowered my price below what would normally be considered a normal selling price. And I’ll ship only to the Continental US.

Once this is paid in full, your amp will ship the next business day.

That’s it!

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I’m an OEM based in Boston, MA, and I'm selling this amp due to age and poor health. I recently completed it and will do my best to explain what I was doing with this amp. I’ve been building audio components for decades.

This is the 2nd copy of this amp that I’ve built (the 1st has been sold), and I did the best I could with the parts I selected for this one.

You will be amazed by the output strength (power-tube-type-dependent), and you can use the EL34, the KT88, or any variant you like that fits this tube family (vast selection, both NOS and current production). Power varies from just under 10 W/ch to over 10 W/ch, depending on the power tubes you select. And, of course, the tone will vary too.

This has a preamp circuit that uses a single EF86 tube and a single 12AX7 tube. This is the best I’ve been able to provide and sounds excellent. As a guitar amp, you don’t need a separate circuit to run a pedalboard. Just place your pedalboard in front of this amp and plug in your guitar. That’s all that you need.

The schematic and info about this amp’s circuit and its particulars are in the three files on the Tubes Store website. Here is the 1st webpage link:

I used this guitar amp and love its sound quality and flexibility. I have purchased many commercial amps in the past, but decided to build my own OEM amp, and now I like it better than anything I can purchase. My last amp before this one was the Carr Rambler, which puts out way more output but isn’t a good studio or practice amp. Its sound was too loud, and the tubes were upside down. This one is perfect and built for longevity. Most guitar amps aren’t.

This amp has the Bassman circuit for tone control, and the tone can vary drastically depending on where you position these knobs. Take a look at the Bassman tone stack to understand what it does.

You are getting a serious deal here: a guitar amp I built for myself and had no interest in selling, and one that is highly flexible depending on the tubes you use. Plus, you won’t find this again. Once it’s sold, it’s gone, and I’m not interested in spending my money or time building another.

This is the 2nd amp of this style that I built, and this one uses the rare Trancendar transformers rather than the much cheaper Edcor transformers I used originally. I wanted to decide if I liked this amp by building the first one, then focused on making it even better, and for me. The 2nd time around was the way to go, and this is what you are receiving now. This amp cost me well over $4,000 plus my time to produce it and CNC its construction, so you are getting quite a bargain. It’s brand new, recently completed, and now available for purchase.

CNC work to build such an amp takes me 3 months to get things right and create all the parts needed. I’m not including my labor cost or the time involved. This amp is being sold below the cost of replacing the parts.

The parts are the result of many decades of work I’ve put into audiophile amps. The 9-pin tube sockets have been purchased from Audio Note and mounted on hanging plates that I had made by Frnot Penel Express. The 8-pin tube sockets are mounted on the chassis top plate, are Teflon-insulated, and cost over $20 each. None of these were cheap, and this amp shines as a result. All tubes point upward, and nothing hangs down where the components get “cooked”. All transformers used, including the internal choke, were custom-made by Transcendar Transformers. The black anodized chassis was CNC’d, then engraved and filled with paint to apply the lettering.

This amp was beautifully made, and nothing was spared to make it the best possible guitar amp. It works extremely well, is totally quiet, and has sound quality that’s emotional but not tubey or thick, so it’s not overpowering.

This is more like a solid-state amp, but it has a rectifier tube that lets you vary the incoming voltage by section, and it has an emotional element that solid-state amps just don’t have. All tubes are pointing upward, so everything will last longer and won’t be affected by heat going the wrong way over your components.

Shipping box dimensions: 18 x 15 x 8.5

Shipping box weight: 23 pounds

Shipping Carrier: UPS Ground

Let me know if you have any questions. This amp was built for me and done as well as I could imagine. I’m an experienced OEM who has been building both tube and solid-state amps, speakers, power supplies, and other audiophile components for a long time. It’s now time for someone else to benefit from my hard work. Hopefully that is you.