jose

Thank you guys!!!

A war on drugs

Happy Birthday!

I've been using a pream based on the ubal/bal and four cfa for my headphones. It is one of the amps I feel most satisfied.

Happy Birthday!!!!

I choose a different earphone from my collection every week but for some reason I always go back to my 007

A detail that I forgot to comment, the slow 1A fuses that I use at the output each HV line of my PSU were blown. The fuse on the HV + rail protected its side of the GRHV but the one on the side - it wasn't so lucky.

I discovered them precisely by Gogo Penguin ... Gondwana Record are signing very interesting artists

I'm listening a lot to Mammal Hands

Thanks for advice Joachim! I´ll work in that direction.

I'm left with this image ...

What have you used as input devices?, Were they macheted? do you have the transformer near the inputs? ....

What the hell is Kapton used for on the potentiometer shaft? I miss the DIY activity that was here until a few years ago but I can understand that, due to this type of thing, the intention to create and give new designs to the DIY community has decreased.

Thanks!!!! My fault…. I was like crazy looking for that album in the bassist's discography. 🙄

I think I have not expressed myself well: For the EL34 I use a single trafo with two windings. One winding per channel (2 EL34 per winding) For the E88CC I use another trafo with its own psu for DC heater. Both types of tubes DO NOT share transformer.

The resistance I have in the current limiter is about 3R. It is interesting what you have commented about removing the CL resistor. Perhaps without this resistor the damage would have been greater ¿?¿?¿?¿?¿?¿? Currently my plan is to build a BH or BHmini PSU just for testing. As for the heating filaments, my T2 mini is configured with the E88CC filaments in DC (with a separate transformer and a PSU for this work) and EL34 with the "standard" way; four tubes with AC with its own transformer. Should I use separate transformers?

^ About Avishai Cohen

HC´s number one rule: have more components in your warehouse than Mouser. Follow the trail of burned components Certified dead: CL resistor, r12, c2m1000170d, 2x bc557b, 2n3904. njm7915fa Changed as a precaution: Q7 10m90s. Q8 & Q9 ksc5026m and 24v diode. The rest of the components passed the test. Total: A few euros and a couple of hours.

Recovered the GRHV, I take a look to the amplifier. Interestingly, all damage is in the area of Servo/OPA27. It seems that most of the transistors are fine although I suspect that the IXTP01N100D are damaged (continuity between two of their legs). Tomorrow I will begin to dismantle the most damaged channel.

Yes, I used Vishay crcw0805 and crcw1206 too. Luckily the tubes are correct. Due to the somewhat peculiar configuration of this amplifier I have skipped my procedure for turning on.

Do not worry. Yes, almost immediately: the right channel burned and then the left channel plus the negative rail of the GRHV. The amplifier had been in "stand-by" for 5 minutes, heating the heating filaments before applying voltage. At the moment I have cleaned the damage on my PSU; I have verified that the low voltage source has also passed to a better life... although it is already ready again (news LM7X15). I suppose that when the OPA was short-circuited it took the LM ahead. I have cleaned the GRHV negative rail board and will install it tonight. About the amp: I still have to check for damage. Both LEDs were on when everything happened. I hope the damages are only reduced to the part of the OPA27. Any suggestions on possible collateral damage? My idea is to remove all parts of that servo and run the amp without it or using the servo on top. I understand that it is possible.

No a good day… OP27 next to VOL618A on fire of both channels and GRHV negative rail dead too. I thought that in this board version that I have this problem was corrected ... I was wrong. I hope I just screwed up the OP27 and not the rest of the sand. Positive, I was able to see that all the LEDs were on. It will take a long time to desolder everything.

I have become a subscriber .... although I do not have speakers on the PC