Hi
I'm looking for the schematics and if possible a kit to re-build a PP El34 amplifier. I have the chsis, tubes, power and output transformers from a Cadence (made in India) amplifier.
I have some experience in electronics and DIY projects, so the complexity wont be a problem.
Any idea how to start?
I'm looking for the schematics and if possible a kit to re-build a PP El34 amplifier. I have the chsis, tubes, power and output transformers from a Cadence (made in India) amplifier.
I have some experience in electronics and DIY projects, so the complexity wont be a problem.
Any idea how to start?
Welcome to the forum. I will move your question to the tube/valve section.
Another Welcome! to the forum. If a published schematic isn't available, forum members can often decipher a lot of information from just a listing of the tubes in use (to guess the likely choice of circuit - there aren't that many in common use) and a few photos.
Be safe, have fun, and all good fortune,
Chris
Be safe, have fun, and all good fortune,
Chris
Thanks for the reply, I´m not at home now to take better fotos, but I had the following: one view of the whole amp, but with two modifications I was doing at that time: adding a 6SN7 preamp (which is in the top) and an automatic bias circuit (at the center behind the filters).
The second phot is the pcb for two EL34 tubes and the other two are the PCB of the one channel power source.
Unfortunately, there is not schematics available.
Hope this helps.
The second phot is the pcb for two EL34 tubes and the other two are the PCB of the one channel power source.
Unfortunately, there is not schematics available.
Hope this helps.
Attachments
No schematics, even of the modifications that you've done? You're not giving us a lot to work with. Is there an actual problem or fault with the amplifier, or or are you just generally interested in improving/ modernizing it? Either will require a schematic, which you can draw out for yourself, unfortunately by hand, the old fashioned way. Worst case.
All good fortune,
Chris
If it's any consolation, that effort is what the sergeants in the Army used to call "Good training, men, good training." Not fun while you're doing it, but sometimes options are limited. If you get lucky with a published schematic, you'll lose out on all that fun training
All good fortune,
Chris
If it's any consolation, that effort is what the sergeants in the Army used to call "Good training, men, good training." Not fun while you're doing it, but sometimes options are limited. If you get lucky with a published schematic, you'll lose out on all that fun training
For what is worth, the Eico HF-89 is a pretty simple, straightforward PP amplifier using EL34: https://www.manualslib.com/manual/887362/Eico-Hf-89.html
I typically use 4 sources:
- Digikey/Mouser for capacitors, resistor kits, power/output transformers (I'm UK based, there are better options in the USA)
- eBay for NOS tubes (mostly from Ukraine suppliers), screws, chassis etc
- AliExpress as an alternative for resistors/transformers, also miscellaneous things like sockets.
- HotRox UK for Belton sockets.
For power and output transformers I'd say Edcor and Hammond are the best bet for quality that does not break the bank. The output transformer is, IMHO, the most important component of the amplifier, only second to the speakers.