Search:

Type: Posts; User: Arbutt; Keyword(s):

Page 1 of 4 1 2 3 4

Search: Search took 0.02 seconds.

  1. Replies
    7
    Views
    942

    The unit in stand by.. Only running off a stand...

    The unit in stand by.. Only running off a stand by 10v dc transformer. The mains voltage is switched by relay. At present relay not switching on. 10v dc is present. By not coming on.

    Many thanks...
  2. Replies
    7
    Views
    942

    53445

    53445
  3. Replies
    7
    Views
    942

    Marantz pm6005 now stby only

    I did post another earlier. My phone crashed

    Hoping you can help.
    I was ask to have a look at this.
    It was intermittent on one channel. Played around with the headphones jack and it came...
  4. Replies
    10
    Views
    845

    I understand what you are saying. Well a bit...

    I understand what you are saying. Well a bit anyway ;>). I'll do my best to get it right without the power amp.
  5. Replies
    10
    Views
    845

    Many thanks helnholtz. I'll do that later

    Many thanks helnholtz. I'll do that later
  6. Replies
    10
    Views
    845

    I was going to do that anyway. As an option not...

    I was going to do that anyway. As an option not sure on what values of resistors to use as yet
  7. Replies
    10
    Views
    845

    OK the owner built his own power amp and decided...

    OK the owner built his own power amp and decided that it sounds better without nfb. He said he tried various resistor and cap arrangements. But settled for no negative feedback. He fitted a steroe...
  8. Replies
    10
    Views
    845

    Audio Stereo valve pre amp NFB

    I'm just about to complete a build for someone. And he wants a 2 - 3 way NFB switch on the front of his pre amp. The switch has been fitted.
    Now he owns a power amp that he built without NFB and he...
  9. Replies
    11
    Views
    446

    Many thanks for all your help. It's now sorted....

    Many thanks for all your help. It's now sorted. Mostly ground issues . And few lead address. I've learnt a few things about ground placement in the last few days. arbutt
  10. Replies
    11
    Views
    446

    Hi pdf. I'm not sure on the g1 question.. As I'm...

    Hi pdf. I'm not sure on the g1 question.. As I'm more self taught... I have removed the centre tap from the heaters and connected it to the same as the 0v from dog house to the power tx. The pots do...
  11. Replies
    11
    Views
    446

    Hello people. Been busy today but I have made...

    Hello people. Been busy today but I have made some progress. Loudthud was on the money. I have removed the 2 red wires and add one and grounded on the power tx. It so much better channel 1 is great...
  12. Replies
    11
    Views
    446

    Thanks for that. The cap on the bias pot I added...

    Thanks for that. The cap on the bias pot I added an extra 10 uf as I could see a little ripple. The main cap is 100uf 100v. Fitting the 10uf made no difference. I will look at it tomorrow and do the...
  13. Replies
    11
    Views
    446

    super reverb amp clone issues

    Hello

    I have a noise issue on a clone
    It came in to me with a note saying just dont sound right, the owner did not make it
    I replaced 3 pre amp tubes and power tubes
    Bias cap and pot, input...
  14. Replies
    41
    Views
    1,660

    Many thanks to you all for the help. I have done...

    Many thanks to you all for the help.
    I have done what chuck said and it's working perfectly.
    Only think I haven't done is the 91k as I didn't have any.
    I have ordered some and will change.. I'm...
  15. Replies
    41
    Views
    1,660

    Thank you Chuck. I had to look twice at this....

    Thank you Chuck. I had to look twice at this. Thinking it's my circuit . Thought you were taking the piss as the British will say :)
    I will do this and report back

    So I will leave you guys alone...
  16. Replies
    41
    Views
    1,660

    Both channels were wired the same and both...

    Both channels were wired the same and both channels were slightly distorted at a higher level . The bias was fixed and at 25ma per tube. Tubes are now stock Russian brand unknown. Tested ok on a...
  17. Replies
    41
    Views
    1,660

    Morning . Had a read last night on AC and DC long...

    Morning . Had a read last night on AC and DC long tailed pair pi. On valve wizard web site As jazz p bass said. I sort of understood it .
    I've decided to go for AC long tailed pair.
    I'm going to...
  18. Replies
    41
    Views
    1,660

    Thank you Chuck . I will look at one later and...

    Thank you Chuck . I will look at one later and post up when I want to use. And see what you guys think. I want to get this thing finished and off my bench.
    Mr a
  19. Replies
    41
    Views
    1,660

    Yes chuck I have a pi circuit for each channel .

    Yes chuck I have a pi circuit for each channel .
  20. Replies
    41
    Views
    1,660

    It's a stereo power amp with 2 x 6v6gt per channel

    It's a stereo power amp with 2 x 6v6gt per channel
  21. Replies
    41
    Views
    1,660

    I'm not going to redo the whole circuit. Just...

    I'm not going to redo the whole circuit. Just gutted the pi and clean it all up .As it was looking un tidy .
    Want to re do PI so I can use fixed bias.
    It's going to be a stereo power amp for HiFi...
  22. Replies
    41
    Views
    1,660

    Thanks I'm going to be using 6sl7 as the pi. Do...

    Thanks I'm going to be using 6sl7 as the pi.
    Do you see issues with this. I know the pin outs are different. I looked at it this morning. It's wasn't looking tidy anymore . Hence why I have...
  23. Replies
    41
    Views
    1,660

    Morning. I decided this morning to start again...

    Morning. I decided this morning to start again with the pi stage on this amp. I have removed all the components from the pi just leaving the tube base with heaters connected.
    Customer was keen from...
  24. Replies
    41
    Views
    1,660

    Thanks helmholtz. I will have a look tomorrow....

    Thanks helmholtz. I will have a look tomorrow. I can see this has 2 x 220k going to ground. I thought the idea of having a trimmer I could tweak it up. But it looks like in going to have to go...
  25. Replies
    41
    Views
    1,660

    Ok so to redesign the pi circuit . Any reason not...

    Ok so to redesign the pi circuit . Any reason not to go with a paraphrase type ?
  26. Replies
    41
    Views
    1,660

    Ok looks like I've fluffed it up. If I remove the...

    Ok looks like I've fluffed it up. If I remove the fixed bias and fit cathode will that cure it or improve matters.?
    Thanks for the help
    A
  27. Replies
    41
    Views
    1,660

    Sorry helmholtz. You were right I forgot to write...

    Sorry helmholtz. You were right I forgot to write in the gnd reference on the 1st picture.
    I have quickly drawn out what the circuit is . Not brilliant but that is my drawing
    Thanks again.
    51072...
  28. Replies
    41
    Views
    1,660

    I don't know hence im asking you guys. The...

    I don't know hence im asking you guys.
    The circuit for the pi I saw online but can't find it since.
    The amp sounds good and works well . But when turned up just has a little distortion.
    When I...
Results 1 to 28 of 89
Page 1 of 4 1 2 3 4