Then I would first check so pin 3 (kathode) is to ground and measure voltage on pin 1 anode. If all ok then disconnect R5 from V3 pin 3 kathode and measure again.
Oooooops stajo & Salas diode connected the negative side to V1 pin 3😱
I'm not justifiying but the strong light that I use caused my big mistake....
I'm not justifiying but the strong light that I use caused my big mistake....
Thats a show(current)-stopper🙂
But I checked some pages ago. Didnt you say channel was down also Before you put diodes there?
But I checked some pages ago. Didnt you say channel was down also Before you put diodes there?
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Thanks for support, the story it's a little bit long: this morning I discovered that grounded heaters was not well connected & tonight the reversed diode, I'm an electronic CRACK
😡
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Thanks for your interest but still I don't know, I have a very busy day!!!!!!! I will let you know.
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First I used the same reversed diode but no sound left channel, chenged for a new diode and now both channels sounds OK, but my Denon DL103R needs more gain isn't enough Partrdige 977 1:6 so I have to change for a new MC step-up 1:10 or more....
Nice that you repaired it Merlin. Well done. Can you hear the rough supply's hum or buzz at all or the circuit rejects it enough?
BTW maybe 1N4148 diodes which are small current and very low capacitance can be best bet there for lifting the cathodes.
Salas if is not to ask too much could you suggest a 3rd stage to have moe gain, I'm very pleased with the SQ of Partridge 977 only that I need more gain.
Hmm it will reverse absolute polarity if its only one tube. If you will use an adapter for 6DJ8 / ECC88/ 6922/7308 in the second stage it will give +4dB over the 6SN7 without adding stages BTW.
I used 61dB before for that cart with DCB1 and 30dB amp and it was alright on 90dB+ speakers. But its subjective also about what you and me feels "loud" enough.
What impedance line input you drive now with the Itch? Maybe you lose some signal on low impedance volume pot line preamp also that 6SN7 can't drive strongly?
What impedance line input you drive now with the Itch? Maybe you lose some signal on low impedance volume pot line preamp also that 6SN7 can't drive strongly?
I use the Itch with:
-ECC81 mu-follower, 100k input pot (headphone amp for Sennhs HD600)
-#26 preamp, 100k input pot (lineamp)
-ECC81 mu-follower, 100k input pot (headphone amp for Sennhs HD600)
-#26 preamp, 100k input pot (lineamp)
How can loading much the 6SN7: changing the pot for another with more ohms?
Have I to change something or simply buy a couple of adapters 6SN7-ECC88?
Have I to change something or simply buy a couple of adapters 6SN7-ECC88?