So the leds are a part of the audio chain,no V3 no light,no the leds are lit.
No they are glowing when MM is on.
But now to the next newe problem I have about twice the signal out from one channel,it is in both MM and MC.
Dont know is this is the cause of it but when (the power was of) accidently
shorted one of the biggest caps (2,2uF) to ground the side that is nearest to the input.Could some of the regulator have taaking dammage of this??
No they are glowing when MM is on.
But now to the next newe problem I have about twice the signal out from one channel,it is in both MM and MC.
Dont know is this is the cause of it but when (the power was of) accidently
shorted one of the biggest caps (2,2uF) to ground the side that is nearest to the input.Could some of the regulator have taaking dammage of this??
So far I messaured that all the voltages to the tubes are alike L and R.
But I found 2 Zeners (ZD2R and ZD3R are shorted ).
I´d love to have a schema now..... 😉
But I found 2 Zeners (ZD2R and ZD3R are shorted ).
I´d love to have a schema now..... 😉
They're across the output, so remove what's connected and check the wiring around the rca if you've been moving stuff around.
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I messaured 0 ohm across the output of course 1 channel sound lower that the other.
I ordered 2 new zeners.Are they som sort of protection?
I ordered 2 new zeners.Are they som sort of protection?
Did you check the wiring on that RCA?
Lift one leg of one of the diodes and measure again, should eliminate both the diodes if there's no obvious short.
Lift one leg of one of the diodes and measure again, should eliminate both the diodes if there's no obvious short.
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Yes I desoldered The RCA cable from the board and the short is on the board.
I am going to desolder the zener to.
I am going to desolder the zener to.
Yes they both have short. I´ll have to wait for the new ones to arrive.
Are they som kind o f protection those 2 zeners?
Are they som kind o f protection those 2 zeners?
I’m no expert but to prevent an initial surge on the output I would suggest, plus discharge at power off too.
I use Tiger Torroids in Norfolk. Superbly quiet, all voltages incl HV.
Get your transformers wound on ‘stabilized’ cores with a GOSS band. You must mention it’s for audio so he selects the right core and knows you can tolerate zero mechanical noise. I get mine cloth wound and double varnish impregnated.
The contact is Stephen Foster. A transformer typically takes 2-5 days.
Tiger Toroids is a British company offering a fast and flexible solution for transformers and sinewave inverters.
He does exports as well.
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Hey folks. I’m interested in building one of these Bigbottle phono preamps but haven’t yet read much about them and don’t know the cost of PCB and components - or where to start learning more about it. I just got an urge to build a tube phono preamp..
Would anyone like to suggest a good place to start for someone who’d like to build this?
Thanks!
Would anyone like to suggest a good place to start for someone who’d like to build this?
Thanks!
The thread on audio addicts in the UK is probably a good place, or contact Oli (bigman) directly.
Great phonostage
Great phonostage
Thanks Simon. Nice of you to say [emoji3]
Its better now than when you heard it. Got rid of the excitable valves!
Great idea! My recommendation when ordering transformer is to avoid Audiophonics. I have been waiting for more than two months and they dont respond to questions.
After a few hours of work, here is my progress. Waiting for tube sockets and BF861B. I've decided to go with BF instead of 2SK369, for now.
I'll mount it on test chassis until I decide what kind of chassis I'm going to build.
Transformer is wound with more copper (winding density), B=1.2T, with electrostatic shield between primary and secondary. I've bought multiple transformers from them to date and they are simply excellent. The biggest (for tube amp) was 1000VAC secondary, for my GM-70 tube amps.
Images in full size (right click, copy image address and paste in new window):
I'll mount it on test chassis until I decide what kind of chassis I'm going to build.
Transformer is wound with more copper (winding density), B=1.2T, with electrostatic shield between primary and secondary. I've bought multiple transformers from them to date and they are simply excellent. The biggest (for tube amp) was 1000VAC secondary, for my GM-70 tube amps.
Images in full size (right click, copy image address and paste in new window):
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I have a strange problem. The tube heaters don't work. Tubes don't get any voltage at pins 4 & 5 (PCC88) and 4 & 9 (ECC83).
If I remove the tubes from sockets, I have 7.87V at those pins. When I insert them, I get 0V between those pins ... I tried inserting the tubes separately, but no luck.
Other than that, I notices the LEDs don't work, tried to flip them, no luck.
Relays are working when I toggle MM/MC switch.
Please, help.
If I remove the tubes from sockets, I have 7.87V at those pins. When I insert them, I get 0V between those pins ... I tried inserting the tubes separately, but no luck.
Other than that, I notices the LEDs don't work, tried to flip them, no luck.
Relays are working when I toggle MM/MC switch.
Please, help.
Well, you should have nearer 7v at those pins so I suggest you need to swap the 2.7v zener to a 2v zener and go from there.