I just finished building my first tube amp, the KT88 single ended amp on the Blueglow Electronics website and it sounds amazing. Now I'm looking for a companion phono preamp to go with it. I'm looking at the one in the RCA Tube Manual right now, but there must be others. Any suggestions?
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Check out the phono preamps on Pete Millet's site (pmillet.com). He has a really interesting LR phono preamp and a pentode phono preamp. He also has a power supply for the LR unit. I've built several of those and they're excellent. No capacitors in the signal path, only resistors and inductors.
Or the original Phonodude from which the above schematic is a clone. It's very good (I built it myself). The first tube (a 5755) is quite affordable. Just type in Phonodude on the search bar. You will see the schematic is identical, only the valve itch uses different tubes.
I’ve built many but this and the one I built at a museum are the only one’s I keep going back to. Simple enough to build point to point and what I recommend.
After more than 25 years of faithful service, it seemed that it might be time to redo my phono system. After all, I like to think that I've picked up a few tricks in the intervening years... The old system consisted of a VPI HW17-II, a Linn Ittok LVII tonearm, and a Troika cartridge. The Troika was a substitute for my previous cartridge, a Technics MM that I sorely miss. Given that the Troika cannot be retipped for anything less than a California mortgage payment, new MCs are priced like the fashion accessories that they are, and that the deck end of the phono system still worked...
- SY
- Replies: 735
- Forum: diyAudio.com Articles
One from me
Walter
Hello,
with the nr. 418 of Audioreview in Italy I have presented a phono tube circuit with the pcb.
In photo the boards completely mounted.
It is a passive riaa.
In the second photo there is a board for HT regulated with fet; it is dual mono.
In addition there is an other HT regulated but with a single Fet. This is a less complicate otpion.
Last photo is a pcb for supply for filament with a LM350T.
Walter
with the nr. 418 of Audioreview in Italy I have presented a phono tube circuit with the pcb.
In photo the boards completely mounted.
It is a passive riaa.
In the second photo there is a board for HT regulated with fet; it is dual mono.
In addition there is an other HT regulated but with a single Fet. This is a less complicate otpion.
Last photo is a pcb for supply for filament with a LM350T.
Walter
- waltube
- Replies: 14
- Forum: Tubes / Valves
Walter
The circuit of post #9 is a low-noise moving magnet phono preamplifier of my design, using shunt feedback to realize the 47 kohm input resistance with reduced thermal noise. It works quite well, but it is not suitable for cartridges that require a really low load capacitance: it has a minimum input capacitance of about 90 pF (with all DIL switches off) due to the full Miller effect in the input stage. There is no PCB, I just built it point-to-point.
Might be good to mention your intended phono cartridge(s). Some are extra fancy or extra picky and might be a special case. Some, like low output MCs need a different design from conventional MM/MI cartridges.
All good fortune,
Chris
All good fortune,
Chris
https://phonoclone.com/diy-pho3.html
I successfully built this as my first project. Turned out pretty great. Only issue I had was physically locating the rectifier tube too close to the big choke. It resonated externally audibly, but was solved with a small capacitor between the rectifier output and the choke. It's been used just about daily for a few years now, and I'm very very happy with it!
I successfully built this as my first project. Turned out pretty great. Only issue I had was physically locating the rectifier tube too close to the big choke. It resonated externally audibly, but was solved with a small capacitor between the rectifier output and the choke. It's been used just about daily for a few years now, and I'm very very happy with it!
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