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Old 28th February 2011, 08:17 AM   #691
hesener is offline hesener  Germany
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Hi, the additional resistor I put in is in series with the C10/C11/C14 parallel block. My explanation was just to illustrate how I soldered it in - basically, I took out the leads of the caps from the gate trace and put the resistor in between there. I didnt put a resistor in series with the gate.

thanks for the hint on the collector of the cascode transistor, wayne. That may probably vary also with the current in the device, correct? I noted that in my version both channels had about 23mV across the 10Ohm resistors of the input stage, so the current they are running at is lower than in the schematic that has been shared here (sorry I forgot who that was) with the voltage levels inside. Guess the best way would be to measure the response against RIAA and adjust R11 (and possibly R12) accordingly.

best regards
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Old 28th February 2011, 08:28 AM   #692
nar is offline nar
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Quote:
Originally Posted by hesener View Post
Hi, the additional resistor I put in is in series with the C10/C11/C14 parallel block. My explanation was just to illustrate how I soldered it in - basically, I took out the leads of the caps from the gate trace and put the resistor in between there. I didnt put a resistor in series with the gate.

thanks for the hint on the collector of the cascode transistor, wayne. That may probably vary also with the current in the device, correct? I noted that in my version both channels had about 23mV across the 10Ohm resistors of the input stage, so the current they are running at is lower than in the schematic that has been shared here (sorry I forgot who that was) with the voltage levels inside. Guess the best way would be to measure the response against RIAA and adjust R11 (and possibly R12) accordingly.

best regards
It seems fairly lower than what I have in my setup, around 43-47 mV if I recall. NP stated to use IDSS matched devices with about 5-6mA IDSS as a minimum . So, top end of the GR grade - as a minimum -, whilst all BL are fine (after matching).

Could you show us a schematic drawing of how you connected the 22 R ? Because now I don't get it


Best,

nAr
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Old 28th February 2011, 02:54 PM   #693
hesener is offline hesener  Germany
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exactly as in post 675 (my simulation schematic), with R1 as 22 ohms instead of the 0.01 ohm that is shown there. I will take a picture soon.
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Old 1st March 2011, 08:04 AM   #694
nar is offline nar
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Ok, thanks. I'm not in mod mood nowadays, lots of things to do at work for the concerts, and I am in the middle of an UGS build too

Best,

nAr
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Old 9th March 2011, 06:24 PM   #695
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I'm planning to make Pearl phono with switchable gain so i can be able to choose between original 55db gain and something about 48db. The idea is to put jumper wire in R15 and a resistor with a jumper parallel to R16 so i can lower resistance then jumper is connected.
Is everything OK this this 'idea'?
Do i have to adjust C9?
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Old 11th March 2011, 09:03 PM   #696
wayne is offline wayne  United States
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Here is a Pearl two schematic with some voltages shown. Remember the Voltages are approximate. The front end is variable depending on the transistor matching and current range. If you want to ghange gain vary R14.
Attached Files
File Type: pdf Pearl2Votages.pdf (45.9 KB, 248 views)
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Old 12th March 2011, 10:45 PM   #697
ungie is offline ungie  Canada
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Anyone know where a nice, finished chassis like this can be purchased in Canada or the US?

Thanks!

Andrew

Quote:
Originally Posted by nar View Post
Click the image to open in full size.

Enclosure is HiFi2000 Galaxy GX383 10mm silver faceplate, all aluminum, perfect dims for Pearl II boards those chassis really are about the best value money can buy

Best,

nAr
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Old 13th March 2011, 11:24 AM   #698
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Hello Andrew

About a year ago I had similar needs, did a quick search, and found nothing comparable in USA or Canada. I ended up purchasing this very same enclosure directly from HI-FI 2000 in Italy. Transport was not cheap, but I am happy with the product.

Feel free to send me a PM if you would like further details.

Pierre
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Old 13th March 2011, 09:36 PM   #699
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Quote:
Originally Posted by ungie View Post
Anyone know where a nice, finished chassis like this can be purchased in Canada or the US?

Thanks!
Andrew
I can only really recommend Par-Metal. They aren't the very prettiest but can be customized a bit and do look quite nice. They can punch holes for connectors and switches if you give them dimensions, and the prices are reasonable... (they don't sell any "pre-configured" that I know of)

AMB uses them to good effect, such as this preamp which is a par-metal, with an extra thick "front" panel for the front and back. I think he had the panels cut by front panel express. (more info on his preamp here)

I compiled a short list of chassis suppliers a couple of years ago. The boutique ones don't stick around long it seems. that thread

Otherwise, it seems most of the good chassis are overseas. Mayeb it's a similar effect to this one: Made in USA
A short essay on why Paul Graham thinks much of the US is ugly ;-)
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Old 13th March 2011, 10:35 PM   #700
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I have that preamp case from Par-metals with the thicker face plate.
It is substantial.

Vince
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