Ping Jim or Tubes, scratching my head over wiring gain and selector switch?

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Bill Epstein

It looks like the volume control eyelets



Are L-R: left output, ground, ground, right output, left input, right input, can you confirm?

The switch has got me switched!

Are the stock RCAs left, ground, right?

Clarinet, of course



Then the switch:



I'm confused by the 3 large eyelets staggered to the right of the 12 small. The traces to the balance control seem to indicate that the first 6 are left and then the second six right but I can't figure out what's hot and ground  :scratch:

Maybe I should just hardwire at the rear of the chassis with extension rods. Tubes, is that what you did?



Bill Epstein

Oops. meant to ask which is right and left, not hot and ground.

Bill Epstein

Re: OK, I've had enough coffee
« Reply #2 on: 1 Oct 2008, 01:11 pm »
   :duh: :duh: :duh:  Continuity test did for all: selector, jumper the balance control and the gain pot :duh: :duh: :duh:

tubesforever

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Bill,  Glad you found all your pickup points.

On my Clarinet, I required 4 inputs so I used a Carsen electronics switch and mounted that as close as I could to all the RCA inputs.  Then I ran the output of the switch to just one of the three inputs at the back end of the board.   I would select the center input if doing this again. 

Up front where the stock selector mounts, I jumpered just the positive right and left to the next leg.  At the center where the balance pot goes I picked up the right and left positive and took that to my Dale Vishay stepped attenuator.  Since this is all common grounded, I picked up a ground at the volume pot points and ran this right and left.  I ran the output of the attenuator to the appropriate leads. 

The wiring is very clean and simple. 

The incoming signal cap on the Clarinet is a 0.10uf value and can be bypassed as long as all your sources have DC offset.  Mine do, so I use a silver wire to bridge these traces. 

My Clarinet is simply dead quiet.  It has a quieter noise floor than the Cornet 2.  It was so quiet, many people that heard my Clarinet thought it was not powered or not connected.  When the music began they were immediately aware that this is a very high performance line stage.   That was with the Silver Supreme Mundorfs and teflon bypasses. 

I know you are going to love this piece!

I will try to post some pictures later so others can see this in the archives.

Cheers!

Bill Epstein

Is DC offset a spec you look up or something you can measure?

tubesforever

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See below....

tubesforever

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Most techs will test for DC output of a source on a digital scope.  I do not have this equipment at home.  

If your equipment is commercial, I would expect it to have DC offset built into the unit.

If you are in doubt you can add the cap until you get everything source wise tested.  The teflons are so sonically transparent I would definitely use the FT-3 or an equivalent in this position.  I am thinking of doing the same because I take my gear on the road.  I don't always have a way to control what is being plugged into the Clarinet.  If I do this, I plan to put a switch in place so I can bypass or filter based on my circumstances.

I tried Vitamin Q's, K40Y9's and the Teflons.  The one sounding the best was the silver bypass wire.

BTW on the Cornet 2 Jim uses the same value 0.10uf cap at the signal input and with this I get zero woofer pumping.  I gotta hand it to Jim.  I think he set this low pass filter at about 4-8 hz from what I remember reading.  It really works great and it sounds better than any phono stage I have compared it with side by side.

Jim can you elaborate on this a little?  Is my memory correct on the low pass for the C2?  Is it about the same for the Clarinet?

Cheers!


hagtech

You can measure for DC on a source just by using a DVM.  It will be rare, and I doubt you have any.  The CLARINET can handle 0.1V dc offset no problem.  Maybe more than that.  As long as it doesn't change! 

I forget which inputs are L/R.  Just have to ohm it out.  The volume control has a really wierd pinout, pull the spec for the stock part and copy that.  The "eyelets" are either mounting holes or feedthroughs (connect traces from top of board to bottom).  It's always confusing for me as the board mounts upside-down in the chassis.

The rolloff on the CORNET is set to about 15Hz.  I put it high so that is doesn't pass too much rumble.  The CLARINET rolls at 10Hz. 

jh


Bill Epstein

Re: In case others were wondering about switch pinouts
« Reply #8 on: 2 Oct 2008, 09:15 am »
Thanks guys.

balance control:
Gr, L in, L out, Gr, R in, R out
I prefer to move the speakers so I jumpered'm with resistor lead cut-offs

Volume control:
L out, Gr, Gr, R out, L in, R in

Switch:
Open, Open, Open, L in, L in, L in, Open, Open, Open, R in, R in, R in
       L out                                                              R out

The three diagonal holes above are duplicate right inputs.

I think this is right, should I check Snopes?  :lol: