I would like to try how a 4 tube el34 PP triode fixed bias amp sounds for guitar. Plate voltage will be around 400 or 475.
I think I will need a new opt for this, the one I have now has a 1.75K primary.
What would be a correct ( range) for primary opt impedances for this amp?
In my search for information I found a Mullard datasheet that specifies Ra_a for two triode push pull amps, but they are cathode biased, don't know if this would affect things though. I attached a part of the datasheet. The full datasheet can be found at http://www.r-type.org/pdfs/el34.pdf
Gratefull for your help
I think I will need a new opt for this, the one I have now has a 1.75K primary.
What would be a correct ( range) for primary opt impedances for this amp?
In my search for information I found a Mullard datasheet that specifies Ra_a for two triode push pull amps, but they are cathode biased, don't know if this would affect things though. I attached a part of the datasheet. The full datasheet can be found at http://www.r-type.org/pdfs/el34.pdf
Gratefull for your help
Attachments
I would like to try how a 4 tube el34 PP triode fixed bias amp sounds for guitar. Plate voltage will be around 400 or 475.
First question: Why? What are you trying to achieve?
In particular, what are you trying to achieve that you couldn't achieve with a single 12AU7 in PP? Or by borrowing a triode-wired Dynaco ST-70 ?
I have VDV70/100 HiFi Monoblocks with 4 x EL34 Triode wired parallel push pull.
Output Transformer is 2K Ra-a, B+ is around 480V, gives 45Watts out.
Never tried putting guitar through them. Wasn't incredibly impressed by their HiFi performance, prefer my Baby Huey design with a couple of 6V6 giving 10 Watts.
Cheers,
Ian
Output Transformer is 2K Ra-a, B+ is around 480V, gives 45Watts out.
Never tried putting guitar through them. Wasn't incredibly impressed by their HiFi performance, prefer my Baby Huey design with a couple of 6V6 giving 10 Watts.
Cheers,
Ian
@Thoglette Yes I could disconnect the preamp from my tube guitar head and feed it into a seperate poweramp. But I will start to experiment again with it, and I would like t keep it in one package. A 12au7 in push pull will not cut it loudness wise playing in a band.
@Gingertube That is great info Ian. Luckily a guitar amp is not a hifi device. I can get my hands on a 2.2K OT, this should work I hope.
Will a lower plate voltage affect the needed primary impedance?
@Gingertube That is great info Ian. Luckily a guitar amp is not a hifi device. I can get my hands on a 2.2K OT, this should work I hope.
Will a lower plate voltage affect the needed primary impedance?
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