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Old 24th February 2013, 11:40 PM   #1451
6L6 is offline 6L6  United States
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UKToecutter - Would you please PM me with your email? I have a few questions that you can best answer. Thank you!

Russellc - No, I haven't yet. 3 channels worth so far... It's not a problem, it's a challenge!
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Old 25th February 2013, 12:22 PM   #1452
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6L6. what can you tell me about your build?
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Old 25th February 2013, 02:20 PM   #1453
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Quote:
Originally Posted by coils View Post
Blink, your transformer is a good choice, 2x24 v coils is perfect, I wish I had one. You dont need a center tap, although with dual secs, you can always make one. If you want split rails, you should do as NP has drawn in the FirstWatt and Zen articles. Run two rectifiers instead of one and ground the middle of the psu, that will stop iduction on your ground wire.

The confusion was because I used a single bridge, as in the original, and gave me 0 zero volts because I measured without the GND.

Redid everything again and found that the wires are in 48V AC.

All mounted only with a bridge, 4x MUR3020W, and was connected to 0.29V for 1 hour.

Very good sound, but there was still a slight hum, so I thought, I'll switch to two bridges, and used the KBPC3504W. I got the feeling of having reduced the level of tinnitus and it seemed more fluid sound, but perhaps it is the placebo effect!

It's a matter of doing more experiments, although the MUR are of 35nS and faster than KBC, have to find bridges faster than KBC ...
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Old 25th February 2013, 05:12 PM   #1454
zoe is offline zoe  United States
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Quote:
Originally Posted by Blink_PT View Post
The confusion was because I used a single bridge, as in the original, and gave me 0 zero volts because I measured without the GND.

Redid everything again and found that the wires are in 48V AC.

All mounted only with a bridge, 4x MUR3020W, and was connected to 0.29V for 1 hour.

Very good sound, but there was still a slight hum, so I thought, I'll switch to two bridges, and used the KBPC3504W. I got the feeling of having reduced the level of tinnitus and it seemed more fluid sound, but perhaps it is the placebo effect!

It's a matter of doing more experiments, although the MUR are of 35nS and faster than KBC, have to find bridges faster than KBC ...
when using single bridge was there hum with grounded inputs?
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Old 25th February 2013, 05:17 PM   #1455
Marra is online now Marra  United Kingdom
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Thanks for the tip NS heres a couple of less fuzzy pics.
Aluminium arrives tomorrow so I should,fingers crossed, have a working amp in a few days time.Heatsinks on the diodes is a copy of Buzzforbs V3.

Click the image to open in full size.

Click the image to open in full size.

Last edited by Marra; 25th February 2013 at 05:19 PM.
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Old 25th February 2013, 05:25 PM   #1456
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Quote:
Originally Posted by zoe View Post
when using single bridge was there hum with grounded inputs?
It's always when I connect the imputs I hear a small hum.

With a bridge or two I hear, but I think with the two seem to give less buzz. I will test more ...

If you disconnect the RCA cables is okay, like a stone ...

I removed the 8 sinks in MUR3020W (pcb channel), they are cold, seemed antennas.

Last edited by Blink_PT; 25th February 2013 at 05:30 PM.
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Old 4th March 2013, 08:48 AM   #1457
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Originally Posted by Blink_PT View Post
It's always when I connect the imputs I hear a small hum.

With a bridge or two I hear, but I think with the two seem to give less buzz. I will test more ...

If you disconnect the RCA cables is okay, like a stone ...

I removed the 8 sinks in MUR3020W (pcb channel), they are cold, seemed antennas.
So do I. There is hum when I connect input signal. I cannot fix it.
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Old 4th March 2013, 03:46 PM   #1458
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disconnect one of the RCA's. i'll bet it's no hum then
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Old 4th March 2013, 04:04 PM   #1459
Zen Mod is offline Zen Mod  Serbia
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here we go again

put fat wire bridge between two pcb main ground points
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Old 4th March 2013, 04:09 PM   #1460
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