audio-talk

Yes I thought thats where you were coming from. But at the sound cost of two 1,000 uF electrolytic capacitors.

Yes, but if you didn't couple the cathodes, then at least the individual cathode resistors would have balanced the current. Saturating the OPT core is going to do more damage to the ...

They didn't put the balance facility in anyway.

That's what having the two separate cathode resistors would do.

Coupling the el84 cathodes like that how do you prevent unbalanced current in the OPT primary saturating the ungapped core? If not now, but in a years time as the valves age.

If its the 300b amp I think it is, close matching is not required.

So if I read it right, its one follower to provide B+, and another that looks like its trying to make a UL setup without needing to have a tap on the output transformer. Cant see why a shorted output would cause any problem though. I would guess any HV N channel mosfet with the right pinout would ...

ed wrote: Tue Apr 22, 2025 11:54 am first post here shows a pdf of gremlin circuit.....

https://el34world.com/Forum/index.php?topic=31890.0

infineon say:
IPP80R1K4P7

Ahh, my mistake I saw the words "Tone King Gremlin" but didn't realize that was the name of a product.

Schematic available on the Web.

Yes, but unless I am missing something you don't say what schematic for what amp we are looking for. A link to the actual schematic would be helpful for the rest of us.

Or to be certain what you are getting:

https://www.mouser.co.uk/ProductDetail/STMicroelectronics/STP5N80K5?qs=qzCNEk%252BRr%252BZT3CJhmpUjuA%3D%3D&srsltid=AfmBOoqabkKo_X8QDNqqndigT4D5HFaWwAfy4S6fygswb5rCYHZcL9vU&_gl=1*1f4sbq0*_ga*MTQ0NzY0ODk4Ni4xNjMzMzgxMTM2*_ga_15W4STQT4T ...

It's unlikely to go via opamps but may go via the upsamplier.

"Unless I try with another DAC, could I assume that the output board just went bad when just sitting and not being used?"

Well, its hard to know without schematics and probing with a scope, but if the digital output is not working, its likely that the dac is not being given a signal it can use to ...

I don't have any spare 6DJ8 tubes handy but both are warming up (checked with an IR thermometer)

You should be able to see the glow from the filament in a darkened room (if necessary).

I would guess the led has a built in series resistor that will be correct when used with 12v. So if you use 7v it will be fine, just a little dimmer.

Ant, try a Neurochrome amp, this one would suit-

https://neurochrome.com/products/modulus-86-stereo-kit

Check the specs out, pretty much as good as it gets. Mine killed stone dead any further desire to try other amps. I had an 86 with linear power supply in a dac size case so doesn't have to ...

It was a fucking analogy, none of the things you seem to think I have said were what I actually said.

As a simple way of showing that you are missing the point, if what you say is true, why do biostatistician exist?

1. I think that's being equally unfair to car mechanics.
2. "GPs are generally highly intelligent and, in my limited experience, inquisitive people." Just where did I say they were not?
3. "They're running what is often a £1M+ business as well as tending to the primary health care of many 100s if ...