I built a Tremolo pedal a week or so ago from www.Amplifiedparts.com. It was a fun to build point to point kit project.  Here's the link to the review and video:  http://www.guitarkitbuilder.com/content/kit-review-trill-tremolo-pedal

Quote from: J M Fahey on August 17, 2011, 01:56:04 AM
I think that in this particular case you could buy a new speaker (MODs are excellent and inexpensive) and leave your old speaker aside for some other project.
You might later build some 1 to 15W simple chip-amp to drive it and experiment.
jm2c

This sounds like the right answer to me. 

Quote from: faulkner1953 on August 13, 2011, 01:53:59 PM
I am impressed with the results of your efforts. I am considering a similar effort, and putting the Mod 102 kit in a Vox VT15 cabinet that I acquired that had a bad preamp/effects board. A question.... This cabinet has a 4ohm 8" speaker. Which output transformer would you recommend to match with that speaker, or do they allow a transformer change in the kit? Or would a change to an 8 ohm speaker be the ticket? I have no idea what speaker is in this cabinet. It's marked VT-15 4 ohm S0942. That doesn't tell me much. Thanks

The output of this amp is already at 8 ohms. I used a MOD10-35/8ohm speaker in this build.

Quote from: J M Fahey on August 10, 2011, 01:19:14 AM
*Might* be, depemds on how it's used it may matter or not.
Please post a schematic, at least a hand drawn one of that gain stage and what feeds and loads it.
Does it amplify or is it just a simple buffer?
How is it biased?

Are you sure that gate is open? you should measure a low value (100/500 ohms) Drain-source, both ways, and a diode from gate to any of the others.

LOL... I am not sure about anyof this, I am a Tube guy. But I am getting 0v on that gate. The other JFET has voltage.

This is a MOD kits Reverb unit, and the JFET in trouble is right at the output. I can get verb up to that Jfet but not out. So as a SS Novice I am assuming this is the trouble. I just ordered 2 of the J201 JFETs so I will replace it and see if I was right. 

But be prepared for me to be right here soon LOL...


I will draw out that portion of the schematic and post it soon.

Thaks for the help.

Quote from: J M Fahey on July 31, 2011, 01:50:18 AM
Congratulations not only on your build but on your awesome review. 

Thanks for the kind words Mr Fahey 

I am not a SS guy at all but I am working on a Reverb pedal and all indications are that the output transistor is open at the gate, How do I make sure?

It's a JFET J201 N channel.  All I have is an N channel MPF102 on hand( rat shack). Can I swap this for the J201 or not?

If not where do I look for the proper FET?

Thanks a bunch guys...

Great thread 

I recently got a chance to build and review the MOD 102 Single Ended two tube guitar amp. I got from Amplified parts.com.

I mounted it in an alternative chassis so I could put the amp more easily in a combo cabinet, with a MOD 10-35 ceramic speaker. It sounds terriffic.

If you have been considering building a tube amp kit but weren't sure what to build, this is a great choice for a novice or expierienced builder.  It has excellent blow by blow illustrated instructions.

Here's the build & review link if you're interested:
http://www.guitarkitbuilder.com/content/kit-review-mod-102-diy-guitar-amplifier-kit


Comments are welcome...

Quote from: joecool85 on June 02, 2011, 12:50:47 PM

Quote from: Casey4s on June 02, 2011, 08:51:01 AM
I'll post it in the proper forum when it's finished. It takes a while for the Editor to approve the article and shoot the video, so it' will be a few weeks before it's published and posted.

Sounds good, I look forward to it.

I,ll start a thread in the "Tube" forum section later about the build.

Here's some of the raw photos of building the new chassis, and a few of the cabinet I am re-using from my Champ. I will only actually USE a hand full of all those pics though.

http://s238.photobucket.com/albums/ff243/Casey4s/GKB/MOD%20102/?start=all

Your amp sounds pretty decent    I like DIY just about anything and I also like to see "innovation" and your amp abounds with that for sure. I see you're not affraid to think outside the Cigar box.   

Quote from: joecool85 on June 02, 2011, 08:35:53 AM

Quote from: Casey4s on June 02, 2011, 08:26:57 AM
This week I get to build the MOD (Amplifiedparts.com) 102 SE Amplifier kit. I am much happier in a regular amp chassis LOL, and this is all true "point to point" wiring too.  I am puttining it in a small combo cabinet instead of the head though.

That's neat.  If you don't mind sharing, we'd all love to see that when it's done too.

I'll post it in the proper forum when it's finished. It takes a while for the Editor to approve the article and shoot the video, so it' will be a few weeks before it's published and posted.

Quote from: crane on June 01, 2011, 04:33:37 PM

Quote from: Casey4s on May 25, 2011, 10:52:02 AM
Thanks for the kind words guys.  Working in that little box was a challenge in itself for my 63 year old eyes, my hats off to you regular pedal builders.

Nice sound, although not quite what I'm used to hear from a tube circuit.
The box is quite big actually - you shouldn't complain. I have to handle electronic components that ar 0.02" by 0.01'" small at work - not that's a challenge (although not connected to guitar electronics)
Not sure if these are 0201 or 0402 but still - just to give you the feeling:


Just a curiosity - how long does the battery last - it's having a rough time heating the filament. My guess - 2-4 hours of playing, depends on battery itself.

About 2-3 hours of full on use, if my batteries were fresh to start with.

Yeah my old eyes can't work that small anymore.  I wear one of those visors with the magnifier in front, like Leo Fender, just to seee my hands. 

This week I get to build the MOD (Amplifiedparts.com) 102 SE Amplifier kit. I am much happier in a regular amp chassis LOL, and this is all true "point to point" wiring too.  I am puttining it in a small combo cabinet instead of the head though.

Life is over when you stop learning, not necessarily when you reach a number.

I just took this pic of myself 2 minutes ago, Rock & Roll jeans and a "Nazareth" T-shirt, singing "hair of the Dog" to myself.



For the folks who are unfamiliar with Nazareth and "Hair of the Dog"  here's a video.
http://www.youtube.com/watch?v=R4JjXPe2B4M

Thanks for the kind words guys.  Working in that little box was a challenge in itself for my 63 year old eyes, my hats off to you regular pedal builders.

I was asked to build this tube pedal a few weeks ago and had a lot of fun with it.  I finally got the wrtie-up and demo video fiished.




Here's the write up on the build and a video/sound clip.

http://www.guitarkitbuilder.com/content/kit-review-persuader-tube-drive-pedal