Hi Chris,
thank you for the help. Let me tell you the problem with the unit. May be you would be know of the top what the problem might be.
The unit works fine for couple of minutes if the source is not a phono source. For phono, it doesn't work from the start. It seems that the unit starts self-feeding for low frequencies and the unit starts producing clicking noises louder and louder. The green light is blinking.
Also, I put in new sovtek VTs in there.
Thank you,
Ra
thank you for the help. Let me tell you the problem with the unit. May be you would be know of the top what the problem might be.
The unit works fine for couple of minutes if the source is not a phono source. For phono, it doesn't work from the start. It seems that the unit starts self-feeding for low frequencies and the unit starts producing clicking noises louder and louder. The green light is blinking.
Also, I put in new sovtek VTs in there.
Thank you,
Ra
Hi mr_ra,
Yes. Your power H.V supply is oscillating. More like a monostable oscillator as the H.V. snaps up and down. The green LED's are alternating back and forth in sync, aren't they?
Look at the biasing info in your manual and turn all the bias controls so the plate voltages are within the range in the manual. That's generally 90 ~ 120 VDC on each plate. With new tubes it should stop oscillating. Also check that all the 100 R resistors are okay and that the plate current is shared between all 6922 sections with 30% worst case between highest to lowest. That means your tubes in the pass section will have all sections matched. Use a dynamic conductance meter for this.
Why he used signal tubes for this is beyond me. I'm guessing he had a ton of 6DJ8 / 6922's to use up. He is passing around 36 ~ 40 mA total current here. A single 6V6GT would have made more sense, or a 6080 (I guess he used them up).
-Chris
Yes. Your power H.V supply is oscillating. More like a monostable oscillator as the H.V. snaps up and down. The green LED's are alternating back and forth in sync, aren't they?
Look at the biasing info in your manual and turn all the bias controls so the plate voltages are within the range in the manual. That's generally 90 ~ 120 VDC on each plate. With new tubes it should stop oscillating. Also check that all the 100 R resistors are okay and that the plate current is shared between all 6922 sections with 30% worst case between highest to lowest. That means your tubes in the pass section will have all sections matched. Use a dynamic conductance meter for this.
Why he used signal tubes for this is beyond me. I'm guessing he had a ton of 6DJ8 / 6922's to use up. He is passing around 36 ~ 40 mA total current here. A single 6V6GT would have made more sense, or a 6080 (I guess he used them up).
-Chris
Thank You!!
Chris,
I finally got some time over the weekend to work on Counteproint and thanks to your suggestions and help, Chris, I was able to find the problem. Your help is greatly appreciated. Thank you!!!!!!!
This is a great sounding piece of equipment and I am very glad the problem was finally found. Thank you again for your help and have a happy holidays!!!
Ra
Chris,
I finally got some time over the weekend to work on Counteproint and thanks to your suggestions and help, Chris, I was able to find the problem. Your help is greatly appreciated. Thank you!!!!!!!
This is a great sounding piece of equipment and I am very glad the problem was finally found. Thank you again for your help and have a happy holidays!!!
Ra
The 4 22uF 450V Xicon lytics in the hi voltage PS section
Greetings Mr. Anatech,
I came across this post as I am looking at an SA3000.
Rather than trying to trace the circuit I am wondering if you would be able to
tell me (without spending a lot of your time)
the arrangement of the 4 22uF 450V lytics in the high voltage power supply section
right after rectification and after
the 1st 100uF cap. (C502 C503 C505 C507)
I wonder if all 4 are pre-post regulation or are two of them exclusively for phono and the other 2 for line stage.
Thanks a lot.
Greetings Mr. Anatech,
I came across this post as I am looking at an SA3000.
Rather than trying to trace the circuit I am wondering if you would be able to
tell me (without spending a lot of your time)
the arrangement of the 4 22uF 450V lytics in the high voltage power supply section
right after rectification and after
the 1st 100uF cap. (C502 C503 C505 C507)
I wonder if all 4 are pre-post regulation or are two of them exclusively for phono and the other 2 for line stage.
Thanks a lot.
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