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SOLD: 12AU7 SRPP Configured Preamp


tlarwa

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I am the first owner of this hand built preamp, and have enjoyed it immensely with my 6L6GC-based SET amplifier and OB speakers (and Cornwalls before that). I am only selling to fund a preamp build of my own (it will be my first). The only change to the original design is that I replaced the coupling capacitors with Jantzen Superior Z caps, which was Blair's recommendation (and a significant upgrade). The amp is in terrific condition and has no issues. I have shipped many pieces successfully, and have perfect feedback here, on US Audio Mart and on Ebay (softrideguylg). Shipping is a $25 flat rate in the CONUS.

From the builder (Blair Chapman) in his original sale ad on Audiogon (I am the first owner). A link to the original ad is also included (scope images are referenced in the original Audiogon ad):

https://www.audiogon.com/listings/tube-12au7-preamplifier-blair-chapman-2017-08-20-preamplifiers?show_listing=true

This preamplifier is a 12AU7 tube based preamp in SRPP configuration. Features a layered plywood chassis, 2mm thick 6061 aluminum top plate.

- Gold plated RCA connectors

- Low noise toroidal power transformer

- Power supply is all point to point, but mounted to a piece of 1/8" fiberglass

- Audio circuit is full point to point

- High quality new tube sockets

- Alps (Real and NOT eBay replica crap)

- RCA tubes

If you look at the images, this unit is dead flat from 20Hz-20kHz! Look at the sine waves at 20Hz (Sorry, it is hard to snap a picture at 20Hz), 1kHz and 20kHz.

I have been doing this for many years and maintain my reputation as one of the most honest and reasonably sellers. Please let me know if you have any questions.

I rate my gear 8/10 due to the DIY nature of my gear. All components, minus tubes because I prefer older tubes are brand new and high quality. The smudge looks on the top plate are simply finger prints. It is a swirl sanded look that I will clean with alcohol before shipping.

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Bump for a simple but really nice sounding tubed preamp.  No issues or disappointment with this one!  I’ll consider fair offers but I’ll keep it as s second active preamp before I give it away.  Thanks!  

 

BTW, I talked to the builder, Blair Chapman, and the gain on this preamp is about 17.  I use it with a 5W SET and it performs admirably on my 98dB speakers.  The Alps pot has a nice slow taper and offers a lot of control.  

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