Tweed Overdrive Special

[tubenit]

First off, thanks to DaGeezer for sharing ideas and inspiration for this amp.
He has communicated with me off forum for several weeks about some ideas he was trying.


Originally this amp was a Carolina Overdrive Special (using a D-type tone stack)  but was refined to use a 5E3 "tweed" tone control instead of a D_mble type tone control. Now the amp is called a Tweed Overdrive Special

This is sort of a cathode biased D_mble typology amp where I used a 5879 pentode in the second gain stage of the OD.
It has the most sustain, overdrive, harmonics and overdriven clarity of any amp I have built or played.
I can easily get the musical "blooming" type feature playing this amp. I can still get that feature with the VVR dialed down to 1/3!!!! 

So it does NOT have to be loud to get those dynamics.
I am confidant the overdrive is in the preamp and OD section. 

It sounds closer to what I see on U-toob as a Trainwreck.
It has more crunch, chime, blooming and sustain thatn the cathode biased D_mble that I built.
I can get notes to sustain into feedback and it sounds like a very musical sustain that blossoms.

I tried it with the band & got more compliments on this amp than any that I have brought to play (about 7 or so different amps).
Sometimes an amp sounds good at home but not with the band. This one sounded excellent with the band.

I honestly don't play well enough to fully take advantage of what this amp is capable of doing tone wise.

Soundclips are here: http://www.soundclick.com/player/single_player.cfm?songid=9488477&q=hi&newref=1

http://www.soundclick.com/player/single_player.cfm?songid=9490676&q=hi&newref=1

DaGeezer's soundclip (which has much better playing): http://www.zshare.net/audio/786814058ef04507/


With respect, Tubenit
EL34 Edit: This top most post in this board will always contain the most current documents for this build

The main Amp building forum discussion about this amp can be found here
http://www.el34world.com/Forum/index.php?topic=9638.0

Here's a picture of the pre-drilled board


This predilled board can be found on this page
http://www.hoffmanamps.com/MyStore/catalog/parts12.htm

The current materials list, schematic and layout diagrams are right below here

Edit EL34:
You can use these two documents for my turret boards for assembly tips
https://el34world.com/Hoffman/instructions.htm

https://el34world.com/Hoffman/files/CommonHookups.pdf

[EL34]

Geezers amp review

Observations of the amp in a live setting (Dance cover band I play in) thru a 1x12 closed back cab, ported, w/ an Eminence Legend 1258.

The amp sounds better live than I hoped, especially the overdrive!

The "Fattness" control basically serves as follows;
*Country/Clean Rock/Motown stuff = Fattness pot all the way OFF.....this gives a nice mid dip that is very Blackface-like. Makes my PAF HB equipped strat sound like a Tele (a Good Thing).
*Blues/Classic rock = Fattness pot turned up ~~3/4 gives a nice mid boost that helps cut thru the mix. Nice growl when digging into the strings.

The Overdrive is quite unbelievable.....the tone I've had in my head all these years (& have spent countless hundreds of $ on OD pedals searching for it) is MINE!
We do a pretty good version of "China Grove" & the OD nails that tone, both in the opening chord progression and in the solo. Pinch harmonics just scream.
Basically any OD tone you want is there (except Metal, of course) & easily obtainable with simple adjustments that are easy to replicate/remember. Reponds perfectly to the guitar volume & tone, too.

It's really hard to describe just how much I enjoy playing this amp!

[tubenit]

BnWitt found a few minor discrepencies between the schematic and layout. There should be corrected now.

IF anyone find any more, just work with the schematic which is Geezer's and is correct & then leave me a PM .

The "flipped" layout will have the OD level & tone wired differently. It sort of a hybrid 5E3 style. Geezer used that initially and then switched it to the true 5E3 style.

We also revised the clean level pot wiring with an optional wiring.  The original is good also. Strictly a preference thing here. Either sounds fine.

With respect, Tubenit

Hoffman Turret Board for the TweedOD is 11.5" X 3.125"

EDIT:  I added the schematic that I am personally using with my Tweed Overdrive which has VVR.

EDIT  9/14/14:  IF one wanted to add a mosfet CF to the 5879 overdrive tube, I have added a schematic for that. The CF adds some smoothness to the overdrive.  IF you prefer a little more chime and grind in the overdrive , then do NOT use a CF. 

One can still use Doug's original board and simply make a small mosfet CF board  to add this feature, IMO.

[amp_troll]

Hello to everyone.  I built the Tweed OD Special and love it. Thanks to everyone who has contributed to this fine design, especially tubenit and geezer.  I was wondering if anyone has added PAB circuitry (resistors and relays) like in a dumble to the amp with any success.  I am talking about the Tweed tone stack with the single 1M pot, not the Carolina OD with the Dumble tone stack obviously.
Thanks again.  I am new to this stuff, so I am trying to keep my ears open and ask intelligent questions.
I hope this is one of them.
 

[tubenit]

The 5E3 tone stack used with the TOS has very low volume loss to it.  A PAB such is in a Dumblish amp has significant tone loss to it.  This is a way of saying that a PAB in the TOS probably would not be very useful and maybe not much of a boost at all? 

With respect, Tubenit

[amp_troll]

Tubenit,
   I understand, thank you.  Two more question sir if I may. 
1. So what would be a good way of getting a boost in clean mode. 
2.  I built a second TOS identical to the first one. However with the 2nd one, when I turn up the PPIMV more
     than say 1/8 of turn, its starts to squeal and growl and is very thin.  Any suggestions?
Thanks always, I learn so much from you guys.
 

[sluckey]

Swap the OT primary plate leads. Any better?

[amp_troll]

Wow, fast reply, man your great!
I went inside under power with chopsticks and when I wiggled the wires going from the PPIMV 250k-DG pot
the squeal went away.  So I figured I had a bad solder joint. I re-did the solder joints, they are dead short with a fluke. Fired it back up and still squeal.  When I rock the solder tabs on the pot, it modulates the squeal and sometimes goes away.  I used the same type of pot on both, so maybe I just have a bad one.  I will change
out.  I really did not like the quality of both to begin with, but once the first one worked I felt ok.  This is the first amp I built with PPIMV.  What type of pots did you guys use?  If you sell them I will surely buy them from you.
Again always I am humbled on this forum.

[amp_troll]

One more what is advantage to PPIMV? 

[sluckey]

Swap the OT primary plate leads. Any better?

[ChopSauce]

I envision building this amp in a tweed-style combo enclosure & would like to avoid a face with that many pots:

 - Vol
 - Tone
 - Fat
 (OD section/switch)
 - OD/Drive
 - OD/Level
 - OD/Tone
 - OD/Volume
 - Master

So maybe there are a few ones that could be implemented as trim pots, like the OD/Tone in HRMs, or maybe put on some back panel - according to people having used the amp and who know what's worth having at hand?

Any thoughts/comments/criticisms/etc would be most welcome, anyway!

[tubenit]

Consider using "mini-pots" for the tone controls.  I have done that and been happy with the results on a tweed style cab.

The Tweed BluezMeister I built had only an 18.5 inch length chassis and I had 9 pots on it plus on/off, light indicator and the input jack.  It also has a pot for a reverb dwell under the chassis which would count for 10 pots total.

IF you absolutely have to eliminate something, then I'd probably eliminate the master volume for the clean and only have the PPIMV. 

With respect, Tubenit

[ChopSauce]

Thanks a lot for the reply and :

 - nice cab, by the way!

Sounds like the power amp section of this amp aims at being pushed ...

[DougGuy]

This sounds like a very fun project!  TweedWeck!  Say it like Sylvester!  Are there any updated links to the sound files posted that are now expired?  I'd like to hear this amp. 

[ChopSauce]

From: https://ampgarage.com/forum/viewtopic.php?p=422463#p422463

https://www.soundclick.com/music/songInfo.cfm?songID=11527276

https://www.soundclick.com/playerV5/panels/audioStream.cfm?songID=9488477

By himself, does it seem.

[clarkleach]

Do you think this circuit would be compatible with the iron in a gutted Hotrod Deluxe?
If so, any speaker recommendations?

[TIMBO]

Hey mate, The hot rod power transformer may be a bit light on for the heater supply.
But you could add a small power transformer to supply the extra heaters.
The HT supply should be OK.
Not much of a speaker guy, but some of the Jensen speakers will work.

[CharacterZero]

Would the Tweed Overdrive Special fit inside the chassis that Hoffman has in his store?  It is listed as 17"x6.5"x2.5".  I considering building this amp or a Bassman AB165 type amp eventually and want to start buying some parts.  I am new to doing a scratch build and am not entirely sure how to gauge a blank chassis size with a given number of tubes and circuit size, etc.  What are the best ways to approach this type of planning?
Thanks,
Tyler

[tubenit]

You could possibly make that work, but I would recommend a larger chassis with a 20 inch length instead of 17. I would be concerned with increased noise at idle in a smaller chassis given it's a reasonably higher gain amp than something like a Fender.


With respect, Tubenit

[Grees01]

Hey there. I know this topic is a bit older, but as I was browsing thru the different amp designs in the Library, I was looking for sound clips or video clips to listen to of these many different circuits. I got to this one, with so much praise for how it sounded, that I wanted to have a listen. I clicked on all available links to no avail. Some of them go the hosting site, but none of them actually play anything. At least that's what I experienced. Can someone provide working links to this amp to have a listen to please.
Thanks in advance
G.

[tubenit]

Here is a sound clip of the Tweed Overdrive Special.    Bluesy Story by Jeff S S | SoundClick


The preamp of the TOS and the Carolina Overdrive Special were different.  The power amp of both were the same topology and component values with the exception that the COS had VVR allowing me to record it more overdriven more easily.


So this recording was the preamp of the TOS into the COS power amp with VVR. 


With respect, Tubenit

[Grees01]

Hey Tubenit, I listened to the link that you provided, and also found one more of yours, courtesy of the amp garage website, with you playing some pink floyd style lead. That sounded really sweet. It was this link https://www.soundclick.com/music/songInfo.cfm?songID=11527276 with the 6k6 tubes?  I took a quick look at Frank's tube information; this tube has a plate dissipation of 8.5 watts? I need to take a look at the schematic, I am assuming this was a push pull amp, so approx 15 watts? What effect's were used? For sure I can hear the delay, maybe some reverb as well. Can you provide a little more detail on this particular sound clip. Really sounds lovely.
Thanks in advance.
G.

[brewdude]

I believe that a pair of 6k6’s in push pull is likely around 10 watts output.

[Grees01]

That's right, I forgot, wasn't thinking clearly. That would be 17 watts at max plate dissipation, and 10-11 watts at 60-70% dissipation right? Thanks for sharing.
G.

[tubenit]

Just a delay pedal dialed pretty low.  Then in the mix down, I added light compression, EQ, and a more delay.   No overdrive or distortion pedals at all.

The amp was around 8watts or so by my guess.  The 6K6 tubes seem to break up pretty early to my ears compared to 6V6.


If you build an amp with a 275-0-275 PT and use a 5Y3GT rectifier, you'd get about 305v or so on the plates.

IF you used a GZ34, you'd about 357v on plates.  If you used a solid state rectifier, you'd get about 385v on plates.  So, you could use 6V6's or 6K6's with a PT like that.   

With respect, Tubenit