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Old 6th December 2017, 07:02 PM   #2851
6L6 is offline 6L6  United States
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2SK170BL or LSK170 B

Only the 4 in parallel at the input need to be reasonably matched.

I know the Gerber info is out there somewhere, I'll try to find it.
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Old 16th December 2017, 02:29 PM   #2852
folkdeath95 is offline folkdeath95  France
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Quote:
Originally Posted by 6c4c View Post
Check connections of R13 (to Q4 gate and GND) And value of R13
Being ridiculously superstitious, I don't dare to thank you too quickly for your advice, but since it seems to work for the time being since I re-soldered R13.
Crossing my fingers....
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Old 18th December 2017, 05:55 PM   #2853
folkdeath95 is offline folkdeath95  France
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A question converning gain: reducing R14 from 1kohms to 300ohms increase the gain from 55dB to 65dB.
Is it possible to go higher by reducing R14 again, or will it cause problems to the circuit?
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Old 18th December 2017, 06:26 PM   #2854
jackinnj is offline jackinnj  United States
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Default Bet you haven't seen this before:

Output impedance of the first gain stage -- about 416 ohms. I would have though it was lower. (I used two different coupling capacitors -- that's why the curves vary at low frequency.)

This will (should) affect the values of the passive RIAA compensation network.
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Old 18th December 2017, 06:52 PM   #2855
6L6 is offline 6L6  United States
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folkdeath, at really high amounts of gain you would be better served by a Pre-Preamplifier (head amp) or transformer.

What cartridge are you using?
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Old 18th December 2017, 07:13 PM   #2856
folkdeath95 is offline folkdeath95  France
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It was a theorical question.
I use a modified DL103. 65dB is OK for me (the pot of my amp is at 12 o'clock for normal listening level).
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Old 5th January 2018, 07:05 PM   #2857
canute is offline canute  Denmark
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Smile Dip switch for selection of load (MC)

Would it have (significant) bad impact on sound quality if the optional load resistor at input was made up of at list of resistors connected to a dip switch in order to have the opportunity to change the load?

My idea would be to have a small board with the switch - either at some stands glued to the PCB or right behind the input RCAs...

Another thing : what about having more inputs - and a rotary switch like ELMA in order to be able to have more turntables connected at the same time?

Finally : those of you that are using low output MCs - are you using the Pearl 2 without SUT or prepre?

I have been so lucky that I have bought a set of unfinished Pearls from a fellow member of our community - and now I am Loki g forward to finish the build.
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Old 5th January 2018, 07:12 PM   #2858
6L6 is offline 6L6  United States
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DIP switch for input loading would work well, it's been done before.

The selector switch idea is good, I don't think it would be a problem.
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Old 5th January 2018, 07:24 PM   #2859
KevinHeem is offline KevinHeem  United States
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Pass Labs use dip switches on the XP-15 for adjusting load, so they must be ok.

I use a cartridge with .4mV output and no SUT setup with Pearl II.
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Old 5th January 2018, 09:18 PM   #2860
McQuaide is offline McQuaide  United States
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I just added 3 position rotary switches to mine for gain adjustment. Works quite well. I run .25mv carts with no stepup.
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