Success (Alas, Temporary)
OK, hooked things up, and it actually played music. Only listened for a minute or so, then put it back on the bench. I was waving my soldering iron around and heard ZIP and something fried. Dumb!!! I will look at it tomorrow.
Anyway made some measurements across resistors, as shown below. Some differences between channels in a couple places, even though most of the JFETS were pretty well matched, except the LED part and the output buffer.
Do they seem reasonable?
OK, hooked things up, and it actually played music. Only listened for a minute or so, then put it back on the bench. I was waving my soldering iron around and heard ZIP and something fried. Dumb!!! I will look at it tomorrow.
Anyway made some measurements across resistors, as shown below. Some differences between channels in a couple places, even though most of the JFETS were pretty well matched, except the LED part and the output buffer.
Do they seem reasonable?
Attachments
HOORAY!
I went back and reconnected things, and everything lights up and looks OK.
Darn lucky!
Re-checked some voltage drops:
R2 (below Q1) - 2.3 mA
R9 (above Q5) - 6.7 mA
R7 (below Q5) - 7.3 mA
R10 (above Q2) - 4.2 mA
R6 (below Q2) - 4.0 mA
R12 (above Q6) - 7.2 mA
Look OK Salas?
Thanks!
Doug
I went back and reconnected things, and everything lights up and looks OK.
Darn lucky!
Re-checked some voltage drops:
R2 (below Q1) - 2.3 mA
R9 (above Q5) - 6.7 mA
R7 (below Q5) - 7.3 mA
R10 (above Q2) - 4.2 mA
R6 (below Q2) - 4.0 mA
R12 (above Q6) - 7.2 mA
Look OK Salas?
Thanks!
Doug
Thanks Salas,
RC, they are some "vintage" RelCaps.
I think I will get some more. I just wanted to get something working before ordering a bunch of "audiophile" parts. Right now I have a Multicap and a WIMA for coupling. I will see which I like better. I have some russian k40's, but they are .47 uF. The output caps are Angela tin foil.
Also, fortunately I had some Rikens left over for resistors.
Thanks for your encouragement and help.
I will keep you posted on things as they burn in.
Doug
RC, they are some "vintage" RelCaps.
I think I will get some more. I just wanted to get something working before ordering a bunch of "audiophile" parts. Right now I have a Multicap and a WIMA for coupling. I will see which I like better. I have some russian k40's, but they are .47 uF. The output caps are Angela tin foil.
Also, fortunately I had some Rikens left over for resistors.
Thanks for your encouragement and help.
I will keep you posted on things as they burn in.
Doug
Hi Salas
Still on the parts hunt !
Don't want to use any 'Unauthorised Parts'...
...but...
I found some 'nice' high-stability 1.6megs today.
Should be OK in the 1meg positions ?
Yes ?
Cheers
Si.
P.S. cap-pickers...
...what USSR silver-mica's do people like around here ?
I read the larger ones in the 'metal-cans' are good for bigger values, like 47nF & 15.5nF...
...anyone tried them ?
Still on the parts hunt !
Don't want to use any 'Unauthorised Parts'...
...but...
I found some 'nice' high-stability 1.6megs today.
Should be OK in the 1meg positions ?
Yes ?
Cheers
Si.
P.S. cap-pickers...
...what USSR silver-mica's do people like around here ?
I read the larger ones in the 'metal-cans' are good for bigger values, like 47nF & 15.5nF...
...anyone tried them ?
I haven't really listened to it yet Salas. I just plugged it in to see if it worked. I need to re-check it after my boo-boo, but wasn't planning on listening to it until it has burned in some more. It did not sound very good after one minute of playing.
Thinking about capacitor options now. You use the Russian siver mica for RIAA, right? What about the 0.1 coupling cap?
I have an AR "The Turntable" with a new base and with Marc Morin's mass loading (using Linn springs and then adding weight (about 1.5 kg !) to the sub-chassis to get all three springs equally compressed.) Really settles the suspension down. Looks fugly though.
Currently have a Grado gold in Linn Basik LVX. Want to try a DIY tonearm. Got some nice spruce, since I build violins as another hobby. Marc also suggest getting a Grado MCZ stylus, which he says makes a HUGE improvement. It costs about $175 I think.
Thinking about capacitor options now. You use the Russian siver mica for RIAA, right? What about the 0.1 coupling cap?
I have an AR "The Turntable" with a new base and with Marc Morin's mass loading (using Linn springs and then adding weight (about 1.5 kg !) to the sub-chassis to get all three springs equally compressed.) Really settles the suspension down. Looks fugly though.
Currently have a Grado gold in Linn Basik LVX. Want to try a DIY tonearm. Got some nice spruce, since I build violins as another hobby. Marc also suggest getting a Grado MCZ stylus, which he says makes a HUGE improvement. It costs about $175 I think.
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