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Old 4th December 2008, 10:49 PM   #471
Salas is offline Salas  Greece
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Thanks. I sleep in weird patterns.
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Old 4th December 2008, 10:55 PM   #472
Salas is offline Salas  Greece
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Quote:
Originally posted by jonners
I'm using a 2SK170 source follower buffer
What circuit? Rsource or B1 style, or White follower? Did you notice it at all sonically, apart the drive boost?
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Old 4th December 2008, 11:38 PM   #473
Salas is offline Salas  Greece
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Ah, Jonners! I almost forgot. If you find the new gain nicely usable in your system, change the series Riaa filter original resistor (82k//82k) to a single 47k new one, the 6k8 vertical one that leads to the 47nF cap remains the same. Else it will sound toned up in treble.
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Old 5th December 2008, 08:38 AM   #474
jonners is offline jonners  United Kingdom
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Quote:
Originally posted by salas
Thanks. I sleep in weird patterns.
Kalimera Salas! Weird patterns are good - very creative! ''

Quote:
Originally posted by salas


What circuit? Rsource or B1 style, or White follower? Did you notice it at all sonically, apart the drive boost?
Buffer circuit is as below. I didn't notice a sonic difference when I installed it.

Thanks for mentioning the 47K resistor - I had been wondering about that.
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Old 5th December 2008, 01:00 PM   #475
Salas is offline Salas  Greece
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Hi,

If you try at 21V and like the gain, better feed the buffer with a 470R or 1k//1k=500R. It will restore its about original quiescent conditions when it was with higher B+. 11.20ma (151% Idss)
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Old 5th December 2008, 07:51 PM   #476
jonners is offline jonners  United Kingdom
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B+ is now 22V, and a 910R dropper keeps the buffer nicely warm at 11mA

I had no more 6K8 res to hand, so I used 8k2 in parallel with each drain res, giving 3k7. Drains are near 8V.

Playing nicely, gain is adequate, and a +15dB modulation from my test record into the DL110 gives an output at the buffer of 1.1VRMS.

Thanks again for your help, Salas.
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Old 5th December 2008, 07:59 PM   #477
Salas is offline Salas  Greece
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Good to know. Its nice that we hit it with one try. Happy listening!
You not only rotate your volume knob more nicely now, you listen with less noise, which is what excessive gain only contributes to a system, along a short throttle.
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Old 6th December 2008, 01:05 PM   #478
Salas is offline Salas  Greece
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Yet another one. The non cascoded 0.5mV 2 stage version and Vbe Mosfet shunt. Michael made it for his friend that has a Pink Triangle Anniversary with a Roksan Arm. He used a Goldmund pre with phono input, but it is up for sale now.
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Old 6th December 2008, 01:37 PM   #479
Thomo is offline Thomo  United Kingdom
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Nice work there. This morning I built the shunt reg on stripboard, and I'll be testing later.

My hum appears to be a number of things. The armtube isn't grounded. It also seems to be caused by the TT itself! I shall build an external psu for it one day soon, and add lots of damping to the plastic underside too.

Cheers, Lee.
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Old 6th December 2008, 01:41 PM   #480
Salas is offline Salas  Greece
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Hi Lee,

Do that coax thing I showed to bring a part of your hum down at least for now. I will be happy to know your impressions about the shunt later.
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