This is a bit of a nebelous/noob tube question I realise.
I have a Fountain (NZ) 10 watt amplifier that is apparently based on a Mullard design. It sounds really really nice. The highs are pretty good (a bit rolled-off/grainy, but thats excusable), the mids are clear without being brash. The lows are oh so low, but a bit wallowy (but thats excusable too). Its from the early 70s.
The thing is that I will need to move on from this amp as the ECL86's are pretty much unobtainable, and I dont know if I can be bothered with the PCL86 mod as getting matched PCL86's also seems to be getting difficult now.
The thing is that I have had tube amps before, but none of them sounded as good as this one. I know that speaker matching etc could have also been an issue. I have had a World Audio Designs (now World Designs) EL84 amp, and a Carvin EL34 amp (a 2-channel guitar amp, but it sounded not bad for hifi use). This little amp loves guitar (my favourite instrument) - and when distorted gat comes on, it makes the sound really shine!
I am running this Fountain into Lowly KEF Q80s - and boy does it make them sing. I have truly become a tube convert again - as I had my fully modded Sansui AU-999 running thru these before and it sounded nothing like this.
So I want to ensure that any new tube amp I get sounds good. My experience with the WAD amp kind of made my think that EL84's sound a bit "gruntless" and "soft," I would like to stick to EL34's maybe for the power.
Is there anyone who has had experience with ECL86 and who could compare this favourably in terms of sound signature with other common power tubes? I am after a new tube power amp and am thinking of potentially some of these:
OddWatt (with EL34),
http://en.uraltone.com/kits/hi-fi-kits/uraltone-stereo-hifi-pp-el84-v1-1-tube-amp-kit.html (with EL84),
ST-70 KIT (120 VAC)
I have a Fountain (NZ) 10 watt amplifier that is apparently based on a Mullard design. It sounds really really nice. The highs are pretty good (a bit rolled-off/grainy, but thats excusable), the mids are clear without being brash. The lows are oh so low, but a bit wallowy (but thats excusable too). Its from the early 70s.
The thing is that I will need to move on from this amp as the ECL86's are pretty much unobtainable, and I dont know if I can be bothered with the PCL86 mod as getting matched PCL86's also seems to be getting difficult now.
The thing is that I have had tube amps before, but none of them sounded as good as this one. I know that speaker matching etc could have also been an issue. I have had a World Audio Designs (now World Designs) EL84 amp, and a Carvin EL34 amp (a 2-channel guitar amp, but it sounded not bad for hifi use). This little amp loves guitar (my favourite instrument) - and when distorted gat comes on, it makes the sound really shine!
I am running this Fountain into Lowly KEF Q80s - and boy does it make them sing. I have truly become a tube convert again - as I had my fully modded Sansui AU-999 running thru these before and it sounded nothing like this.
So I want to ensure that any new tube amp I get sounds good. My experience with the WAD amp kind of made my think that EL84's sound a bit "gruntless" and "soft," I would like to stick to EL34's maybe for the power.
Is there anyone who has had experience with ECL86 and who could compare this favourably in terms of sound signature with other common power tubes? I am after a new tube power amp and am thinking of potentially some of these:
OddWatt (with EL34),
http://en.uraltone.com/kits/hi-fi-kits/uraltone-stereo-hifi-pp-el84-v1-1-tube-amp-kit.html (with EL84),
ST-70 KIT (120 VAC)
Attachments
The 6BW6 is a member of the rather extensive 6V6 clan. In Noval based types, the 6CM6 is another clan member. Add the Russian 6Π1Π (6p1p) to the 9 pin clan member list too.
Careful review of the schematic provided by the OP shows the power section to be similar to the Dyna ST-35. It's not Mullard style.
Careful review of the schematic provided by the OP shows the power section to be similar to the Dyna ST-35. It's not Mullard style.
Attachments
Yup - down my way it seems. Even fewer willing to ship to NZ. A matched quad can be bought in NZ from a NZ seller for $250NZ. Great. Apparently the PCL86's are a bastard to match - so sellers tell me.
I want more power anyway - quite keen to develop something else - but try to retain this sound quality.
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Slimecity,
We need to know if you are wanting to build a Guitar amp, or a HiFi amp.
If we know what you want, it will help to get you a better answer.
Just having more power if you want a Guitar amp to sound a particular way with medium power is not going to work.
Others in the thread:
Just giving slimecity a few suggested tube types, without a tested schematic is not going to get him very far in building an amplifier.
There are lots of excellent amps out there.
And just as many, or even more opinions too.
The question is, will it be a kit; or a build from a good and repeatable schematic?
(with hints like how to place power transformers, chokes, output transformers; hints on elimination of ground loops; negative feedback or not (substitute an output transformer, and get an oscillator, not an amplifier), triode wired pentode/beam power tubes, etc.
Trying to match the sound of a particular amplifier, may or may not work, especially if it is not using exactly the same loudspeakers.
DIY is fun, sometimes complicated, sometimes surprising, and most often very satisfying.
I encourage slimecity to continue in his quest to build a nice amp.
We need to know if you are wanting to build a Guitar amp, or a HiFi amp.
If we know what you want, it will help to get you a better answer.
Just having more power if you want a Guitar amp to sound a particular way with medium power is not going to work.
Others in the thread:
Just giving slimecity a few suggested tube types, without a tested schematic is not going to get him very far in building an amplifier.
There are lots of excellent amps out there.
And just as many, or even more opinions too.
The question is, will it be a kit; or a build from a good and repeatable schematic?
(with hints like how to place power transformers, chokes, output transformers; hints on elimination of ground loops; negative feedback or not (substitute an output transformer, and get an oscillator, not an amplifier), triode wired pentode/beam power tubes, etc.
Trying to match the sound of a particular amplifier, may or may not work, especially if it is not using exactly the same loudspeakers.
DIY is fun, sometimes complicated, sometimes surprising, and most often very satisfying.
I encourage slimecity to continue in his quest to build a nice amp.
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I agree that ECL86's are getting very scarce and expensive nowdays. Introduced to the market in about 1966, they represent the culmination in integrated small signal triode/power pentodes for AF usage, but weren't produced for a long time, as they were displaced by transistors rather quickly.
Well, the latter one also applies to the PCL86, but due to the - yet - minor interest in P-series TV tubes there still are ample NOS tubes around.
I'd recommend doing the PCL86 modification (= another heater supply), acquiring a certain batch of these tubes and matching them by yourself.
Best regards!
Well, the latter one also applies to the PCL86, but due to the - yet - minor interest in P-series TV tubes there still are ample NOS tubes around.
I'd recommend doing the PCL86 modification (= another heater supply), acquiring a certain batch of these tubes and matching them by yourself.
Best regards!
Tubes do not always match very closely when you have a limited number of them.
You can at least get a little closer if you do the following:
Use separate self bias resistors on the push pull pair of output tubes cathodes (double the resistance of the single common resistor value), and use 2 bypass caps, one for each self bias resistor.
You can then read the voltage across the 2 self bias resistors, and calculate the current of each tube of the push pull pair.
The output transformer will be less likely to saturate on low frequency signals, because the DC currents on the 2 halves of the primary are matched.
Also, you will be able to tell if one tube ages quicker than the other, by checking the individual cathode voltages as time goes on.
You can at least get a little closer if you do the following:
Use separate self bias resistors on the push pull pair of output tubes cathodes (double the resistance of the single common resistor value), and use 2 bypass caps, one for each self bias resistor.
You can then read the voltage across the 2 self bias resistors, and calculate the current of each tube of the push pull pair.
The output transformer will be less likely to saturate on low frequency signals, because the DC currents on the 2 halves of the primary are matched.
Also, you will be able to tell if one tube ages quicker than the other, by checking the individual cathode voltages as time goes on.
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