Going to build this modded Matchless Hotbox. Advise me if you will

[briandress]

Hey guys. Im gonna take the plunge and dive in head first on a build here.

I have most everything in my cart at tube depot but wanted to get some advice on types of caps resistors, pots etc

If most dont matter than thats fine too.

On the hunt for how to put together a power supply for this.

http://diy-fever.com/amps/tube-reactor-pre/comment-page-1/#comment-258891

That is the reference build.

I wonder how I can show the parts I picked out at tubedepot

[briandress]

Here are shots of my shopping cart

[GibsonGM]

I see nothing wrong with what you're buying, but then don't have the BOM here, either.

I don't really like EH tubes...most I've bought I've found to be microphonic....

[briandress]

definitely recommend some tubes. the original builder used an EI 12ax7 and a JJ 12AX7. I got the JJ i think. Not sure what EI is thought it might be electro harmonix. what would you recommend?

I cant find a BOM in his blog post, mostly going off reading. He said lost of the caps are Mylar. Not sure what Mylar caps are.

Wonering about the power supply because he didnt explain how to build it but said it was in a laptop psu enclosure.

[thermionix]

definitely recommend some tubes. the original builder used an EI 12ax7 and a JJ 12AX7. I got the JJ i think. Not sure what EI is thought it might be electro harmonix.

EI tubes were Yugoslavian-made IIRC.  Don't think they exist any more.  Don't think Yugoslavia exists any more.  JJ ECC83s sound okay but they have a habit of shorting.  I've seen them blow a fuse, burn a trace, and smoke a resistor (3 different amps), and I've never seen another brand of 12A_7 do any of those things.  I usually consider the Sovtek 12AX7WA to be a good catch-all X but lately I've been getting noisy ones brand new.  EH and the "reissue" brands have been largely disappointing to me.

Can't tell you what to buy, but make sure you are able to return them if they are microphonic or noisy.

[briandress]

so you used to like EH tubes but what now?

[GibsonGM]

I use JJ's with no ill results, but things can vary.  Aren't they just Sovtek with a red "JJ" stamped on them?   I know Fenders are.   Anyway, JJ's are 'standard', there are millions and millions of them out there.  I seriously doubt you'd ever be able to hear any difference between 12AX7's! 


Honestly, I wouldn't sweat it, Brian.  www.tubesandmore.com (antique electronic supply) is a great source for parts, wire, tubes, etc.

[briandress]

Ok i guess I will start building.

I think Bancika is actually a member here. I think I saw an old thread on this build. I am trying to work out the power supply and what the B+ voltages are. Thats the part that confuses me most about it

[briandress]

Ok only really picked this because it has something that someone has already done but in listening to some sound demos I have found it isnt really what I am going for.

I am looking to build something that is really like a JCM 800 that I can get clean and super gain tones from. So I guess thats two channel. I guess i need to revisit this altogether

[briandress]

what do you think of this as a power supply unit?

http://www.londonpower.com/power-supply/tube-preamp-power-supply

[thermionix]

I use JJ's with no ill results, but things can vary.  Aren't they just Sovtek with a red "JJ" stamped on them?   I know Fenders are.

No, JJs are made in the Slovak Republic.  Sovteks come from the Reflektor factory in Russia.  Internally they are very different looking too.  Fender bought Groove Tubes a few years ago, and most new Fender amps do come with Sovtek tubes that are re-labeled Fender and Groove Tubes.

Back to the JJs, very few of them short out like I described, but it's odd that any do at all.  H-K shorts.  Common for power tubes, not so much for preamp tubes.

so you used to like EH tubes but what now?

No I've never been too impressed with EH.  I don't know what to recommend now, JJs are as safe a bet as anything I reckon.  I have some noisy preamp tubes in my amp right now, pretty much brand new, and I'm not sure what I'm going to try next.

[PRR]

> Don't think Yugoslavia exists any more.

It's complicated. It was always an artificial "country", formed in post-war and then Russian politics. They had good tube factories. When it all fell apart, the factories (at least two) changed to different trade-names, which may not be the names we are sold tubes under.

I do not think you carted "wrong" tubes. I do know that fussy audiophiles are always looking for some "better" tube. So call these "starter" or "debugging" tubes, build, play, enjoy, *then* wonder if some other 12AX7 will bring you perfect joy, and sling your money around like a drunken sailor.

[HamishR]

This is my first post here.  I am relatively new to pedal building but have been building tube amplifiers for over 15 years.  I am very familiar with the Matchless Hotbox, having gigged with one for years, then a Matchless Dirtbox and finally the Badcat Two-tone.  The Badcat Two-tone is virtually identical circuit-wise to the Hotbox except it has a tone pot on the clean channel, and you can completely bypass the entire pedal if you want.  FWIW I think the Badcat pedal sounds better - the power transformer is a little bigger and (I think from memory) it may be slightly more heavily filtered.  So the low notes hold together better.

The circuit is very much a Vox top-boost channel in a pedal.  I think you can probably get the correct power transformer from Mercury Magnetics.  Badcat and Matchless both use Matchless branded caps which are the same kind of thing as Mallory 150s, Mojo Dijons or Sozos.  I would recommend using either of those for coupling caps and silver mica for the pF values.  I would also use 1W carbon film resistors except for in the filtering section where I would use 2-3W metal films.

I've been using JJ 12a*7 tubes for years now and never had one short on me - that's weird!  I don't doubt it but it has never happened to me.  I don't really like anything Sovtek or New Sensor (essentially the same thing) as they just don't last.  I have had good results with (of all things!) Sovtek 12ax7WBs, but in general I stick to JJ these days.  Unless you are mad about tons of gain I would suggest experimenting with the regular JJ 12ax7s and maybe the JJ 12ax7MG.  I have had really good results using one JJ 12ax7 and one NOS GE 12at7 too - so don't be afraid to experiment.  The tubes make a huge difference and believe me you will hear it. 

For hardware I like PEC or CTS pots, Switchcraft jacks and Belton 9 pin sockets.  You can get all of this stuff from tubesandmore.com or tubedepot.com.  Tubesandmore.com have great prices and usually have everything in stock. 

Just be careful about things like grounding, keeping filament wiring as far as possible from signal wires, crossing plate and grid wires at 90 degrees - all the usual tube amp stuff.

Hope this helps!

[briandress]

This is my first post here.  I am relatively new to pedal building but have been building tube amplifiers for over 15 years.  I am very familiar with the Matchless Hotbox, having gigged with one for years, then a Matchless Dirtbox and finally the Badcat Two-tone.  The Badcat Two-tone is virtually identical circuit-wise to the Hotbox except it has a tone pot on the clean channel, and you can completely bypass the entire pedal if you want.  FWIW I think the Badcat pedal sounds better - the power transformer is a little bigger and (I think from memory) it may be slightly more heavily filtered.  So the low notes hold together better.

The circuit is very much a Vox top-boost channel in a pedal.  I think you can probably get the correct power transformer from Mercury Magnetics.  Badcat and Matchless both use Matchless branded caps which are the same kind of thing as Mallory 150s, Mojo Dijons or Sozos.  I would recommend using either of those for coupling caps and silver mica for the pF values.  I would also use 1W carbon film resistors except for in the filtering section where I would use 2-3W metal films.

I've been using JJ 12a*7 tubes for years now and never had one short on me - that's weird!  I don't doubt it but it has never happened to me.  I don't really like anything Sovtek or New Sensor (essentially the same thing) as they just don't last.  I have had good results with (of all things!) Sovtek 12ax7WBs, but in general I stick to JJ these days.  Unless you are mad about tons of gain I would suggest experimenting with the regular JJ 12ax7s and maybe the JJ 12ax7MG.  I have had really good results using one JJ 12ax7 and one NOS GE 12at7 too - so don't be afraid to experiment.  The tubes make a huge difference and believe me you will hear it. 

For hardware I like PEC or CTS pots, Switchcraft jacks and Belton 9 pin sockets.  You can get all of this stuff from tubesandmore.com or tubedepot.com.  Tubesandmore.com have great prices and usually have everything in stock. 

Just be careful about things like grounding, keeping filament wiring as far as possible from signal wires, crossing plate and grid wires at 90 degrees - all the usual tube amp stuff.

Hope this helps!

hey thanks for your reply!! I actually have changed my mind and want to work on something that has like a fender clean channel and then a JCM 800 dirt channel. Maybe configured so that the clean can boost the dirt with a boost switch. I would like to have volume gain and tone on the clean like you say and then the full tonestack with gain and vol on the diort channel.

This is basically the Two Notes Preamp pedals. The clean has a basic tone and the dirt has a full tonestack.

Would you mind terribly helping me work through that?

[briandress]

i reallllly am digging the second pedal in this video. the Renegade.

https://www.youtube.com/watch?v=g02nSC7VWFs