SSTS Preamp build and schem

[Streel]

Hi all, 

I hope this is the right forum for this post.  I was reading through the Preamp forum and I discovered an interesting DIY preamp project that someone had built there, called the "Solid State Tube Sound" preamp. I have a 100 watt s.s amp and I thought this would be a good project to build. The schematics can be found at:
http://members.tripod.com/gillcar/id24.htm
I'm having a little trouble reading part of the schematic, and I hope someone here can help.

There are two versions of this preamp.  For reference: 

The original first design schematic -- http://gillcar.tripod.com/SSTS/SSTPreamp.gif
The second newer design -- http://gillcar.tripod.com/SSTS/SSTSschm.gif
The pcb layout of second schematic --  http://gillcar.tripod.com/SSTS/SSTSpcb.gif
The mod (optional) -- http://gillcar.tripod.com/SSTS/SSTSmod1.gif

I downloaded both versions (original and new) and I want to build the second schematic.  I'm having trouble locating all the pots. I only see the Drive pot at R20 in the mod schem, and the trimpot at R23.  I don't even see the Volume pot. The original schem clearly shows the Volume pot located between C10 cap and Out, but in the new schematic there's no Volume resistor between C4 cap and Out. Where is it exactly?  And I didn't see the Tone, Body, and Gain pots identified on the new schem either, which were clearly identified in the original. Have some of these been omitted from the new design? I want to start ordering the parts but want to be clear on the components I need first. 

I apologize for the beginner questions, I'm trying to learn electronics slowly and read schematics in my spare time, but I'd like to jump ahead and get this DIY preamp going right away. Any help will be greatly appreciated.

Thanks very much.
Streel

[darwindeathcat]

Hi Streel,
  I think that I am the only one on this forum that has actually built this preamp. Before I answer your questions, I must say that while this preamp may not "sound like tubes", it does sound very good. If you check my posts on this preamp in the preamp forum, you will see links to some YouTube videos of me playing harp through it. I cannot vouch for how it will sound with a guitar, however.
  Now to answer your questions. The trimpot at R23 IS the gain pot. I'm not sure why he wanted it to be a trimmer in the original schematic as it is much more functional as a user adjuxtable pot (I used a 100k linear). There are no tone or volume control at all in the second schematic as he suggests each builder would want to add their own prefered circuits here. I agree with that. I added these directly to the output of this circuit with good results (after C4). I used the "stupidly wonderful tone control" and the "better volume control" circuits. You can find them easily by googling those names.
   I did not try to build his first design as it was way to complicated for what this thing does. You should get good results by building the circuit as shown in the second schematic, with the drive mod, using a real pot for the gain, and adding some simple tone and volume to end. I never added a "body" control as a) i have no idea what "body" really means, and b) I never saw where one could add such a control into the second schematic

Cheers
Darwindeathcat

[Streel]

Hey Darwin

Thanks for replying concerning the questions I had.
Yes, you were the one I was referring to in the Preamp forum.
I actually saw your YouTube demonstration vids and commented about them in Preamp forum, but I'll say here again that they were great vids. You did a good job demonstrating before and after tone. This preamp makes your harp sound fantastic. Makes your harp sound very good and bluesy. In your second vid, when you turned the Gain and Drive to max, the effect and tone knocked me out, that was real nice. I'll get this preamp built and try it with my amp, hopefully I'll have success getting a similar tubelike tone also. 

You provided the exact answers I was looking for concerning the schem, thanks very much for clearing that up. And thanks also for the info about the tone control and volume control circuits you mentioned and put into your circuit. I'll search it out and add components to my list.  Last thing I need, I must find a good steel cash box to hold it all, LoL. I liked the way you designed that. 
Thanks again for your help.
Regards,
StreeL

[GB]

Hi... I have looked at the schematic you referenced. Although it is using JFET (presumably) to emulate tube sound it is not ideal. If you are interested I have a better circuit that you could use?
GJB