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Old 16th March 2013, 11:31 AM   #9421
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I got some ft1 to try as RIAA caps. As matter of fact, I think I got every kind. Can't remember. Get used to it as you will need to listen for difference in sound(if any) in tx2575 resistor.
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Old 16th March 2013, 11:42 AM   #9422
Salas is offline Salas  Greece
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Quote:
Originally Posted by RCruz View Post
Another one up and running.

4 x k170 input fets
K72-6 Teflon 15n caps
K71-4 Polystyrene 47n caps
Full on second stage buffer (with fet ccs)

Now listening with a DL160.... no clipping... super silent... dynamic... Tone seems correct, must let it settle for a while, then retrim voltages and serious listenning ahead.
What are those little coils? Anti resonance gate measures? 4xK170 is ~63dB gain, using a HOMC is hardly a way to listen to it correctly, still not clipping is noteworthy though.
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Old 16th March 2013, 12:18 PM   #9423
RCruz is offline RCruz  Switzerland
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Quote:
Originally Posted by buzzforb View Post
I got some ft1 to try as RIAA caps. As matter of fact, I think I got every kind. Can't remember. Get used to it as you will need to listen for difference in sound(if any) in tx2575 resistor.
Beware of FT-1... The thin wires do not help and tend to come loose.... I had trouble with drifting values also.... IMO no go.

The best are FT-3 with alu casing... but no values for the riaa. The K72-6 are bulky but the insides are +- ok (I opened one to see )

The K71-4 polystyrenes are really good.... nice mids, fluid....

Quote:
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What are those little coils? Anti resonance gate measures? 4xK170 is ~63dB gain, using a HOMC is hardly a way to listen to it correctly, still not clipping is noteworthy though.
The coils are the placements for the input / output wires and also he output cap..... Really better than trying to solder those directly on the boards.

I use the DL160 just for the initial burning... I will soon change to the Benz and start serious listening.

Anyway, after an hour, the sound is now very powerfull (I agree that the buffer is better... just need some riaa trimming)... Spatial presentation is awesome, bass is deep and controlled and the highs are becoming sweet.
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Old 16th March 2013, 12:21 PM   #9424
Salas is offline Salas  Greece
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Good.
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Old 16th March 2013, 12:28 PM   #9425
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*A friend tried with single k170 in lieu of 369 for the base circuit the other day although I warned him it is designed around the 369 and then he told me it was bit weird until he found 4 proper ones I had given to him a long ago and used two for stereo. Then all fell into place and he had some audio epiphany moments with some bass galore etc. Conclusion is just follow the tested circuits, they work correctly.
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Old 16th March 2013, 12:37 PM   #9426
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Salas,
Do you know of a good adapter that would allow for easy changing of caps? I haev looked for somthing simple, like the coils, but have not fonud anything. I was considering just doing multiple daughter boards with different caps on them that will fit PCB holes, but still not plug and play.

Thanks RCruz. Ill have to get some of the K71's to try. I have some seimens KS coming. ALso ordered some modern PPS. This is goign to be fun. Just got to talk brother into letting me remove his long enough to listen to newer versions.

Salas,
If we buiilt them as spec'd, what would you do with yourself
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Old 16th March 2013, 01:15 PM   #9427
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Have used Pana PPS and I liked C0G better but let us know. Both through hole though. For large caps, classic tubes building stuff like turret lugs maybe?
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Old 16th March 2013, 01:26 PM   #9428
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Quote:
Originally Posted by buzzforb View Post
Salas,
Do you know of a good adapter that would allow for easy changing of caps? I haev looked for somthing simple, like the coils, but have not fonud anything. I was considering just doing multiple daughter boards with different caps on them that will fit PCB holes, but still not plug and play.

Thanks RCruz. Ill have to get some of the K71's to try. I have some seimens KS coming. ALso ordered some modern PPS. This is goign to be fun. Just got to talk brother into letting me remove his long enough to listen to newer versions.
I use golden inserts like those found in older meridians

PS:
Looking forward to try those resistors have you sent them yet ?
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Old 16th March 2013, 01:28 PM   #9429
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No. I have a bunch of packages that need to go overseas. Will be sending them Monday. Work has been too busy and late to allow for shipping. Haven't been able to get to post office.

PPS will be Kemet/RIFa
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Old 16th March 2013, 01:53 PM   #9430
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Help me think this out guys.
In RIAA,
We are looking at 15nf caps, plus - a 150pf or 300pf I guess. Total 15.15-15.3nf
I assume this is important. Would a silver mica or polystyrene work best?
PCX has 150pf polystyrenes. (Silver mica too).
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