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Old 10th March 2009, 06:36 AM   #1341
iko is offline iko  Canada
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It is interesting that the fellow who wrote the article
http://www.borbelyaudio.com/pics/waagbo2863.pdf
on Erno Borbely web site, has also built and tested opamp versions of mosfet regulators, similar topology to the one I built. He also reported something wrong with the sound of the opamp based one. I don't know, but I like the sound and performance on paper of the last one posted a little earlier. I think we have got here from the beginning, with your initial version, an excellent regulator. On paper these improvements may show, but in real life, perhaps also.
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Old 10th March 2009, 07:11 AM   #1342
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Default Loading R's for my Glider

Still trying to figure this out. The data on my Glider LO says load impedance- 120ohms. Ive tried various R values ( 500, 1k, 10k, 41k, 82k with PRP resistors) and found higher to my liking- though bit too relaxed in the highs. What I hear from others, no-one really loads theirs with anything that high.

So I need to try the Shinkoh's. But what value? Well, if I buy 3 2k4's per channel, I can series-parallel 6 values for each channel- 800, 1k2, 2k4, 3k6, 4k8, 7k2. A pretty good spread. Would doing this have any sonic penalty?

Thx- Kent
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Old 10th March 2009, 11:28 AM   #1343
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not so good you will add the noise from resistor.......


shinkoh is very 3d sound but little soft , try hight value , riken are for you ,the hight are live (too much for me)

150r riken have more live higth then 200r shinkoh (if I remember well!)

I like hight load, more sound stage ,big sound , but the sound start on bright side ,now you know why I like soft resistor
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Old 10th March 2009, 11:51 AM   #1344
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Quote:
Originally posted by ikoflexer
Another detail which might help others: a ceramic 100nF capacitor right at the B+ and GND entrance to the njfet phono is a great improvement (high freq. filtering).



you are right , must do !

and one between the stage ....
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Old 10th March 2009, 12:50 PM   #1345
RCruz is offline RCruz  Switzerland
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Quote:
Originally posted by salas
This extra JFET CCS for the BJT we have checked out here too and we all got somewhat better sound, but Ricardo got the most subjective benefit. Maybe because he uses a cascode first stage. Its code name is ''R6 mod''.

For the 100nF directly on the B+ receiving end to gnd, I have to agree, the more the wire length from shunt to phono, the more work it does. I have recommended that to Ricardo and vgeorge. Always to be used when separate PSU and Phono boxes are employed. You can see it on mine too, where the red and black B+&GND twisted pair meets the phono board.

Here
Hi Salas

The R6 mod is very important... it makes the shunt sound much much better... it is not a subjective impression.

I will do the 100nf mod. (Did you use a russian cap there ?)

Ricardo
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Old 10th March 2009, 12:55 PM   #1346
RCruz is offline RCruz  Switzerland
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Default Re: Loading R's for my Glider

Quote:
Originally posted by kstlfido
Still trying to figure this out. The data on my Glider LO says load impedance- 120ohms. Ive tried various R values ( 500, 1k, 10k, 41k, 82k with PRP resistors) and found higher to my liking- though bit too relaxed in the highs. What I hear from others, no-one really loads theirs with anything that high.

So I need to try the Shinkoh's. But what value? Well, if I buy 3 2k4's per channel, I can series-parallel 6 values for each channel- 800, 1k2, 2k4, 3k6, 4k8, 7k2. A pretty good spread. Would doing this have any sonic penalty?

Hi Kent

I experimented loading my Benz ACE mid output with 460r; 680r; 1k8; 2k2; 27k; 39k; and 47k.

Below 1k8 the sound is muted but the bass is very tight.
With 39k or 47k the spatiality is very good but the bass is loose.

I settled with 2k2 and am now using welwyn RY55 metal film... very good sound indeed.

Next step will be the shinkoh with 2k2 or 2k4. These tants add a lot of space and detail.

In your case I would search near 1k.

Ricardo
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Old 10th March 2009, 01:42 PM   #1347
Salas is offline Salas  Greece
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Quote:
Originally posted by RCruz


I will do the 100nf mod. (Did you use a russian cap there ?)

Ricardo
Yes, a Ruskie PIO it is on the photo. (It is no mod, just a useful add on).
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Old 10th March 2009, 01:53 PM   #1348
Salas is offline Salas  Greece
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Quote:
Originally posted by kstlfido


Salas- thanks. I'll wait on the corrections. Then we are all talking the same part #'s. I will try to design a matching shunt PCB (the R6 mod one) as well.

One thing I'd like to do is to make more room for bigger R's; namely the 2W Kiwame's you and others are using. What is the size of them? I do hate standing them on end- ugly!

-Kent
Hi Kent.

I have started trying to get them together. Can you add pads for a 0.1uF bypass film cap right near to the B+ point on the phono board across to the GND too? Also a CxIn for those with MM version?

Kiwame:

Carbon Film
E-24 class
2W and 5W type, 750 volts DC max
+/-5% (actually +/-0.5%)
Silicon Resin
Light Green
2W (BODY) diameter-4.2mm, length-12mm. (LEAD) diameter-0.8mm, length-28mm
5W (BODY) diameter-9mm, length-24mm. (LEAD) diameter-0.8mm, length-36mm
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Old 10th March 2009, 01:54 PM   #1349
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HI Salas

you thinks that my 45v shunt need R6 mod ? (dual mono ,+/-)


thanks
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Old 10th March 2009, 02:05 PM   #1350
Salas is offline Salas  Greece
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Only with 2SK170GR or with a TO92 mini heatshink on your BC550C, because at that voltage of yours, it is going to dissipate 300mW if a BL takes it to 7.5mA constant current. BC 550C is a 500mW max little bug so I would not trust long time reliability in such use. (Some brands even say 625mW, but I would not go 50% to 75% max constantly and still feel its a good practice, plus the max gets limited a lot in a hotter than room ambient environment as in an amp or shunt PSU box). I would prefer a BL and the BC on T092 mini sink.
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