WELL, I could not resist. QUINN TKT 183 6L6 INCOMING!

[M Fowler]

All I get when I try download the schematic is a red X, any ideas?

Mark

[jaysg]

All I get when I try download the schematic is a red X, any ideas?

Mark

I get that too, which is bloody ironic. Right click and do a Save Target As download. That works. I'm on IE7, fwiw.

[talbany]

I reloaded the image as a slightly smaller JPEG.. So that should cure it.. Sometimes the software has a hard time with large GIF files..FWIW it opened right up in Chrome..

Hope this helps..

Tony

[tubedogsmith]

The OD drive control and OD volume are both 250K?

[M Fowler]

I got the schematic thanks guys.

Mark

[talbany]

The OD drive control and OD volume are both 250K?

Actually
In 183 the OD Drive is 272.2K Audio pot # 021857 CTS
The OD Volume is 285.1k Audio pot # 021857 CTS

Tony

[jaysg]

Actually
In 183 the OD Drive is 272.2K Audio pot # 021857 CTS
The OD Volume is 285.1k Audio pot # 021857 CTS

My recent experiences with CTS pots are that they all read low, so you might want to buy 300K pots if you can find them.

[tubedogsmith]

I scrape my pots to get them exactly where I want anyway but was just checking to make sure that last schem was right. It's easy to get a pot reading 230k or so up to 280k.

[talbany]

Tubedogs beat me to it.. Still post it though

Another way to do it is find a 250K pull it apart take an exacto knife and around the edges of the trace scrape off some carbon.. If you scrape it around the edges away from where the 2 wiper contacts hit the trace you wont effect the pot's taper just the total resistance of the trace it's self..You should be able to add 25-50k this way...I've done this with several pot's and had some success.. Another method is to with a Q tip go around the trace as evenly as you can with MEK or Acetone..I have not tried this method but hear it works.. This method might alter the taper though..

Hope this Helps

Tony

[ampdork]

Having lucked out with some NOS for those previous builds I can say the CTS 250K's I got were all over the place, some below and some well above 250K.

That said with the bass pots I was unable to find a 250K that would measure that high, nor a 500K that low....had to get all gibson on it... either 300K or 350K I forget offhand but with a small handful was able to get a few right on the money.

With regards to newer pots.... unsure how the custom J taper stuff works but most any modern day audio pot is actually two or more linear of differing values spliced together at an angle (like old school audio editing of tape)...
This creates a pseudo logarithmic (audio) taper...
My thought is this....if you do the mek or acetone trick perhaps one would benefit from avoiding hitting the portion of the track where that stuff happens....perhaps this will allow one to get the resistance up while not altering the taper.

just a thought..

[jborders5]

I found the CTS 250K solution (for a price)... I completely forgot I purchased a RS Guitarworks SuperPot to try in one of my Telecasters last year, but never got around to installing it. I don't have my notes in front of me, but it measures just under 280K and is around a 30% taper. The bad news is they're $14.50 each.

http://store.rsguitarworks.net/RSG3.html

[ampdork]

Fender does sell J taper pots! The bummer is they are small PCB deals. You can remove the bracket for board mounting and they work just fine.
good taper but not sure I'd ever use one in a production amp... but for 1M audio's for a home build they might do the trick nicely and for not a whole lot.

[talbany]

Schematic posted in the files section along with the layout..
BIG thanks to Jaysg for the wonderful contribution to the archive!!

https://tubeamparchive.com/viewtopic.php?t=13095

Tony