RE604 SET amp

[Mielke]

Hello,
my plan is to build a SET amp.
The research lead me to think of the ECL (6BM8) imput and driver tube combination. Driver will be the pentode in triode mode, OPT is Tamura permalloy 7002 transformer, rectifier RGN 2004 with chokes for each channel separated and oilpaper cap as first cap in the power supply. It should be stereo.
Negative feedback could be applied from secondary of OPT to cathode of the driver with only resistor in between or maybe negative coupling between the input and driver stage as this sounds better.
Any comments are appreciated as this is only my thoughts of how to build a nice little 1,5 watter.
Maybe someone has an idea for better input/driver tube for the RE604?
It should be a very good amp, as I invested many thoughts, money and time in getting the best components in the world for my idea of sound.
Thanks, Uwe

[panos29]

I would keep it as simple as possible and use as driver a nice D3a pentode, triode connected with a 50H choke load at around 150-170V@10-12mA.

[dipp]

Originally Posted by Mielke

Hello,
my plan is to build a SET amp.
The research lead me to think of the ECL (6BM8) imput and driver tube combination. Driver will be the pentode in triode mode, OPT is Tamura permalloy 7002 transformer, rectifier RGN 2004 with chokes for each channel separated and oilpaper cap as first cap in the power supply. It should be stereo.
Negative feedback could be applied from secondary of OPT to cathode of the driver with only resistor in between or maybe negative coupling between the input and driver stage as this sounds better.
Any comments are appreciated as this is only my thoughts of how to build a nice little 1,5 watter.
Maybe someone has an idea for better input/driver tube for the RE604?
It should be a very good amp, as I invested many thoughts, money and time in getting the best components in the world for my idea of sound.
Thanks, Uwe

Hello,
I wonder how your RE604 project is going as I am at the same situation as you when you posted it. The RE604 deserves a better driver than 6BM8. Why negative feedback? My choice is also RE604 as it is one of Jean Hiragas favourites, and that can't go wrong. I built RE604 monoblocs with RGN2504, Partridge OPT, RC-coupled with REN904 many years ago. I'm not sure if REN904 is a optimal driver as I have no schematic and my knowledge is very limited, but it is working. I have these to choose from: C3m, WE437A, E80CC(two stages in one), ML4, RE304, RE084, RE144, A415, B409. But which, that's my question too. May be REN904 is the right choice. Interstage trafo or driver load trafo make it more complicated and expensive, and with the superior capacitors available today is it necessary with them?
Any comments are appreciated.

[45]

Originally Posted by dipp

Hello,
I have these to choose from:...cut .... E80CC(two stages in one), ...cut ....... But which, that's my question too. ........cut.....
Any comments are appreciated.

The older ECC40 is a better choice. The E80CC may appear (from datasdheet) as a special quality tube but it is not better than the ECC40 in terms of hum and michrophonics. Instead the ECC40 is a rather more linear device.

45

[mik190]

I made ECL82 amplifier. It is perfect for easy listening. It provide 4W per channel, but I used powerfull transformer and individual L-filters for each channels. And I used ECL82 for both stages. Only 1 tube per channel you need.
And it is little in fact.

At the moment I am constructing 2W amplifier at 6C2C + 4P1L with interstage transformer (no capacitors in sound channel at all).

4P1L is unique because it is very-very linear. But it is not little (8 kg)

[dipp]

Originally Posted by 45

The older ECC40 is a better choice. The E80CC may appear (from datasdheet) as a special quality tube but it is not better than the ECC40 in terms of hum and michrophonics. Instead the ECC40 is a rather more linear device.

45

Any opinion on REN904 and the later version AC2?

[45]

Originally Posted by dipp

Any opinion on REN904 and the later version AC2?

I would use the ECC40 because they are very very similar in terms of electrical characteristics and performance but the ECC40 is an amazing low microphonic tube. It is better than most more recent devices!

45

[Mielke]

Hello and sorry for late answer.
Finaly I did EBC11 triode input, 6V6G driver (triode), all capacitor coupled to RE604.
Driver is beam power tube and it works great with RE 604. Input I wouldnt choose pentode this time, but maybe next amp.
Regards, Uwe

[hooman]

ecl82 sonic is amazing ....my frind amp is the parallel pcl82 .and rectifier is mullard gz32.....opt is 4.2 k .oil capacitor in power and he use this tubes to drive fostex .
we use the 211...el34...2a3....in some project ....but pcl82 is expensive hifi in chipe tube

[hooman]