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Thanks Kerry, By the way, some beautiful amps you are building today. Regards Les

Hi Kerry, Thanks for coming back. I think both + and - to ground were the same. All positive rails were fine. All negative rails were up by the same % about 10. With the amp connected. When i found this i did not bother to check anything else with the amp disconnected. Just ordered the fets. Cant try it at the moment as i removed the transistor. Replacement wont arrive for a week. I have some FQPF8n80c FET's which i understand have a PD of 59w as against the originals which have a PD of 179w. Can i try them in there just to see if my Output return to normal? Don't expect to drive the amp with a signal. Les UPDATE: Have replaced the FQP8n80c with the FQPF8n80c and the voltages are back to ~10v and diff is 50mv. I remembered Kevin saying that he was able to destroy the -500v Fet and suggested replaceing the diode with a 30v zener connected between gate and source. Well i had one of Kevins earlier boards which showed 1n4007. Lo and behold somehow i only managed to change the +ve side to zeners and not the negative. So i guess that this fet just gave up. So hopefully all is well again. Is it safe to leave the FQPF8n80c in as i see it has only a Pd of 59w as against the other at 178w

Guys, Thoughts please on the following question: what is the max voltage allowed between the +- outputs to ground? If this voltage is allowed to go greater then what damage is being done to the Headphones long term? I had read somewhere that 30v was suggested. The reason i ask this is that my T2 has been going well, no noises and sound was excellent. So i decided to measure this voltage, it was 50v hot and 100 cold and i asked myself why as i had checked it a few days before and it was under 6v. Decide to look further and found the -560v was at -620v. Measured the series fet (FQP8N80C) and it was sc. Havent replaced it yet but assume this the reason for the high voltage measured on the outputs. With this fet shorted the sound is fine and would not have found this had i not decided to measure. Worrying as this can happen and you will not be aware of it. So this is the reason i am asking about any long term damage by having such a high voltage present. Any comments appreciated as i am about to pass this on to a non tech person. One should also ask how often is it necessary to check this. Thanks Les

Hi Guys, Long time no show. T2 still going well. Need to fix a volume problem with the original Digital Attenuator board. Volume at switch on is not low. In fact it is quite loud. Need to get another copy of updated volumecontroller.zip file that Kerry did. Can someone direct me to it. Did anyone have any trouble with volume at switch on too loud? In my one if i switch on and immediately turn rotary encoder then the volume drops down. I dont know now which version of the software i have used so would like to reload the " updated volumecontroller.zip ". Thanks Les

Thanks Padam, Will start at this and see what happens.

Can someone give me an idea on what a fair price to ask for SR 007 MK2 Serial SZ3. Sadly my hearing just doesn't do justice to them anymore so want to sell. They are still in mint condition with little use probably 200 hours and with carrying case and documentation. They are about 4-6 years old and have been stored in their box when not in use. I am the second owner and i always have used them on KG's amps. Thanks Guys.

Birgir you were spot on and thanks to all. I just used my fingers and rolled the stuff off. That 3m stuff is really good.

They had slid sideways and were half covering the openings. I did try to slide them back.No option but to remove them and reglue. Les

Hi, WTF did they use to stick the pads to early Phones(2000).The crap is like black tar and as hard to get off. I managed to scrap it off the plastic cases but getting it off the pads is a real shit. Any suggestions for removal and what do you use to reglue. Thanks Les

Finally finished my one. Goes back to 2013 but i am a slow builder. Works like a charm, turned on and everything adjusted up as expected. No noise i can detect and as i used heat sinks 4" high i do not have any heat problems. For those interested i used a smoked acrylic top to the amp and put my led's on the top and fitted Kerry's 1" OLED display front center of the amp under they acrylic and with a cool blue display sure looks sexy. I am crap at taking pics so that is why there are none. Thanks to Kevin, Kerry and Birgir for another great project.

Kerry, Just wanted to say that your software is awesome. Had been using the soft that was listed way back when the project first surfaced. It has some problems, yours is simply pure pleasure. Have it installed up in my T2 and just loving everything. Reckon the OLED display is real cool and Volume numbers are " purfect". You asked earlier about noise when using the 12v supply. Can't hear a single thing and the smoothness of this Att is Fantastic. Big thanks also to Kevin. I just taped off the 12v feeding the front end where it connects to the Board. Thanks again for all your efforts. Les P.S Just in case anyone wonders i'm using a Nano and the V1 board.

Thanks Kerry, Noise was my concern to. So my back up plan was to install a small toroid transformer in the p/s and feed a separate 12v to the Att so as to keep it completely isolated from the Amp. Only time will tell, will keep you posted. Curious as to why the spec for the Filaments of the 6922 was specd at 1.4 a when total was about .7a. My ones are running at 7v which i dont like and i will have to add a resistor. With this winding loaded to 1.4a the voltage is correct.

Well i finished my T2 build and it fired up first time and much to my delight with no smoke or flying parts. Have yet to put music thru but there appears to be no noise thru the amp with open inputs. With less than 100mv between + and - and 8v between outputs and ground i think i am a happy bunny. I am about to install V1 of Kevins Attenuator and was wondering about feeding this from a single 12v supply. I was considering taking the spare pin on the power sockets and picking up 12v from the power supply to feed the att. I will use the nano board to supply 5v and 3.3v. Is thisa good or bad idea?. Any other better suggestions.? Want to get this installed asap so i can listen to it. A long build but very satisfied.

Did any one bother to check the 2sk246 fet before soldering it in?. If so how did you test it. By the way also any body thinking of these 2sa1486 which i think HKsouce sells then i think they are Fake breakdown at 400v, cant remember where i got mine from . Les

Thanks, Still a bit hard to see exactly how much higher one is than the other. Any way i just soldered the octals hard down and the 9 pin with the pins just protruding thru the other side of the board. Les