JoaMat

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Kerry, I red your post at 7 in the morning Swedish time. After a few hours of thinking and reading schematics and not getting any viser I did follow your advice to use a diode tester. And whips I found a K216 - Q26 - behaving different to the functional channel, replaced it with the very last spare I got. Now the T2 is playing just wonderful. That diode testing method will be my first choice next time, it´s like a Swiss army knife. When starting the diode test the whole process took less then one hour to get the amp playing. Thank you very much. That goes to all you other people out there, no names, that have contributed to the forum. I´ve read posts forwards and backwards and that have made it possible for me to build the T2. Well, maybe one person should be remembered - Dr. Takeshi Hayashi. Dr. Kevin Gilmore – thanks for your GKSSHV it´s a lovely amplifier.

Thanks Kerry, yesterday I concentrated on the input stage and I replaced Q1,2,3 which didn´t solve a thing (trial and error, not so intelligent). Top batteries voltage are at +10V and Q4/Q5 gates are at -15V. D1 gives the right base voltage and hopefully the Q1,2,3 are OK. What brings the U2 anode voltage down to -15V when it should be around +200V? What effect do Q34,35,36 have, the current thru R9 is 15 mA and R10 is 6mA. edit: one more thing – will a faulty Q4/5 have effect on U2 anode voltage?

Now I´ve done some measurements (I work slow - I´m just an uneducated amateur). Output +: Anode -460 V, Cathode -500 V; LEDs D10, D11 no light Output -. Anode +490 V, Cathode -318V Batteries top voltage +10 V and bottom -500 V. Input stage first tube cathode -27 V, second tube cathode -20 V and gate -19 V. Current thru R9 15 mA and R10 6 mA.

Thanks for your advice Kevin. I´ve changed tube and replaced all three transistors – Q11, Q12and Q25 but the problem is still there. The plate voltage is as you predicted +500 V. What could next step be? I guess that the faulty 60 volt supply is due to something happened in the amp or could it be that a -300 V and -600V from the PSU have caused problem with the amp?

I finished the building of my T2 clone a week ago. The building process went very smoothly and the amp have played just wonderful until last evening when a “gunshot” was heard and there was just noise in the phones. The PSU 60 Volts section measured almost 100 V, just a few volts less then unregulated voltage. May it be the TL783 that has given up for some reason? I took a 60 V supply that was at hand to get all voltages correct from the PSU and connected the Amp. Left channel worked as it should – right channel was dead. Right channels active batteries measure 523 V (-510 and +13 vs ground) and 546 V (-533 and +13 vs ground). All LEDs are lit except D10 and D11. What could be the problem with the right channel? HELP wanted and needed! Joachim

Rodrigo, Connectors arrived today. The feeling when inserting the headphone is wonderful. Your concern to get a good connector is most appreciated Thanks for all the time and work you have put into these Stax connectors. /Joachim

Heat sink for LME498**: http://www.aptaudio....PA_Parts_1.html

Well done Greg!

No, I can´t say I noticed any difference between them two. I also changed the high voltage from +/- 450 to 500 volts so it isn´t really possible to compare them.

OK. I´ve the onboard type and started with the ”1968 current source” and after a week I changed to ixys. Both variants have worked without any problems for me. But since you have the offboards I guess I won’t be much of help for you.

blubliss, What type of PCBs are you using - with or without onboard heat sinks?

horio, I have feeling that I accidental changed your number of Jacks in the sign up sheet. Maybe you better check that up. I´m very sorry. /Joachim

I´m interested in four connectors.

Deepak, Thanks for the info. Tran connected me earlier today and he has promised to send one set of the T2.

Deepak, If anyone of the T2 buyers cancel the buy of a T2 set - I happily buy one T2 set. Just PM me. And THANKS!! to you guys that have made this group buy possible.

Hi Lil Knight, If it´s still possible I´ld like to join in for: 1 set KGSSHV offboard and 1 set KGSSHV onboard Thanks for your initiative.