Help with Tweed Bluezmeister OD tweaks?

[jinx1499]

Hey guys,
I love my Tweed Bluezmeister; the clean channel is amazing, lush and big and has the "bloom" I've always heard about. The OD is solid but a bit shrill (even after adding Tubenit's TEC on V2 and V3). I'm looking for a way to better dial in the sound of the drive channel without ruining the cleans. Can some sort of quasi HRM be inserted to give better control over the eq response? Does it even need to be that involved? Any help you kind folk can provide would mean the world to me - this amp is so close to being grab and go, I just gotta figure out that drive!

For reference:
V1: RCA 5751
V2: CBS 5751
V3: Sovtek 12ax7 LPS

Power tubes: Tung Sol 6l6 STR

I generally play either a 54 or a 62 RI strat through the amp. I understand that "humbuggies" would likely mitigate some of my issue but they're not really my thing. I'd rather just tune the amp to what I like to play.

Thanks again!!

[tubenit]

What type/brand of coupling caps are you using in the OD section?  I am finding that can make a significant difference.   I typically use  Orange Drop PS series, but I've used (sparingly) some MusiCaps also.  I also am
using Vishay Dale RN-65 resistors for the plate resistors.  And I "orient" the cap which has seemed to help also.

I also found that moving the tone stack between those gain stages sounded smoother to me.  I've tried different value plate and cathode resistors but they didn't seem to add much in the way of smoothness to me.

With respect, Tubenit

[jinx1499]

They are orange drops. Think I should swap them out?

[jinx1499]

Also, I'm not sure how to move the tone stack in between the OD sections. Can you break it down for me?

[tubenit]

The Orange Drops that we normally use in the Fender type amps that are polypropelene are not what you want in the OD section. They will sound harsh and lack smoothness.   You want Orange Drop polyester caps, or you can try Mallory 150 caps or try Xicon caps.  Doug may have some Jupiter caps that would work well?   

Do a search in ARCHIVES on "Do capacitors sound different?"   http://el34world.com/Forum/index.php?topic=19534.0

I don't know how to help you any further with the tone stack???  I gave you a schematic with the tone stack (essentially a treble cut) circled in red.   

with respect, Tubenit

[SILVERGUN]

jinx - define shrill
I'm assuming that you mean it's thin sounding with way more highs than mids/lows

Let us know how you would want it to sound (more drive?) and what effect tubenit's suggestion has.

Try this and tell us what you hear:
-Put a .022 cap across the .0047 after the second OD stage
-Also, if you have the 25k pot between stages set too low that would be a recipe for thin

[jinx1499]

Thanks for all the input so far.
When I read tone stack, I thought it would be a TMB or that the TMB of the clean would be moved. I just didn't read the post right. I will look into trying that.

I can expand more on the "shrillness" of the overdrive section:
The OD is thin and as Silvergun referenced, way more highs than mid/lows. It's unbalanced, harsh and doesn't have really any of the saturation and bloom that I'd like. I don't really want jack up the clean section, I just want to modify the components in the OD section that effect the way the frequencies respond in that area. I hope that makes sense.

[tubenit]

With my Tweed BluezMeister,  I think you would be hard pressed to discern which channel is clean vs. overdrive IF I did not have the OD channel cranked but had it dialed in more as a boost. In other words, both channels have a nice FULL sound to them.

MY OD does NOT sound thin at all.  It has good sustain.  Good note definition and sounds very articulate even when doing chording. You can hear all the notes in the chord. I am using the OD more as a boost then trying to get strong overdriven tones.

Hear is a sample.   Start to :46 sec into song is ONLY the clean channel.   From :46 to 1:36 is only the OD channel.  From1:36 to 3:23 is OD +  Zenith pedal.    3:23 to the end is just the OD.

https://www.soundclick.com/html5/v4/player.cfm?songID=12803806

OD PS caps oriented correctly.  Vishay Dale RN-65 plate resistors.  Good lead dress.  And the OD tone control (treble cut) is always filtering out some "highs".

With respect, Tubenit

[tubenit]

Another example.  Mediocre playing and the sound clip is way too long but you get the idea. Only pedal was a delay set very lightly. 

https://www.soundclick.com/html5/v4/player.cfm?songID=10251365

Start to 1:12   clean only
1:12 to 2:37   OD only
2:37 to 3:55    OD & midboost only
3:55 to  End     OD & midboost and PAB engaged.       

IF you listen right at the end of this sound clip,  there is just guitar playing a few notes.  I don't think you will find it thin or shrill.

Can you post an exact schematic of YOUR amp, please?   And then let us know what type of caps you have in the clean section AND in the OD section?  And what type of plate resistors in the OD section?

With respect, Tubenit

[jinx1499]

Whelp...that amp sounds amazing. Way way closer to what I'm looking for. I could stand for the OD channel to have about 25% more gain to get closer to an ODS type tone, but other than that - spot on.

My amp was actually purchased from another guy here in the forums , jonyoungyi. The layout and schematic and everything is in the first post here:

http://el34world.com/Forum/index.php?topic=22132.0

The only changes I've made are the "TEC's" at C and D plate resistors (both 250p) and the 82p after the LTPI coupling caps. It helped, but it didn't put me anywhere near the OD sounds coming from Tubenit's amp.

I've used an em12neo, a emi gb128, and a wgs et65, with the gb128 sounding about the best. Please let me know your thoughts.

[tubenit]

I have spent 100+ hrs experimenting and building D-inspired amps.  And I am going to offer you some thoughts for your consideration.

1)  There was a reason Dumble used the OD PS (polyester) caps & Vishay Dale RN65 resistors in both the clean and
     the OD channel.  They all contribute to the smoothness ( & lessening the harshness) of the OD when engaged.

2)  I think someone can get a fantastic clean channel with regular OD caps like we'd use in Fender amps and regular
     metal film resistors. 

3)  I think using the typical Orange Drops in the OD channel is a recipe for a harsh/shrill sounding amp.

4)  The optimum smoothness in the OD will be there IF you have the OD PS type caps (or something comparable)
     & Vishay Dale RN65 resistors in both the clean and OD channels.

5)  Having said that,  yes ……. I think you can get a reasonably smooth OD with regular Orange Drops in the clean
     and Orange Drop PS series in the OD.

So, where does that leave you with your amp.  My understanding is that you're reasonably happy with the clean channel?  And if so, you probably don't want to change much if anything?  However, IF you can make some slight changes and still love the clean tone but get an improved OD tone ………. then maybe some changes in the clean would also be worthwhile.

[tubenit]

So, being in your shoes …………..  here is option #1

Just make changes in the OD channel. 

1)  remove bright cap off OD drive pot  ( I bet this is contributing to the shrill/harshness)
2)  replace all coupling caps in OD section with either OD PS caps  OR   Doug's Jupiter caps which are polyester.
3)  I'd use either Vishay-Dale RN65 resistors for the plates in the OD section ………… OR some type of 1 watt or
     2 watt metal film resistors
4)  move the tone stack from OD level pot to OD drive pot so that the tone stack is in between the OD gain stages
     and NOT after the OD gain stages.

I think these mods will make a significant difference helping you achieve the tone that you are wanting.

As a side note,  when I want to increase gain in the OD ……….. I tend to dial up the OD trim pot and the OD level pot the most.  I actually have the OD drive pot set somewhat low like around "5"  (12 noon).  I will have the OD trim and OD level 5-7.

Sent you a PM.       With respect,  Tubenit

[tubenit]

Option #2 …………. IF you are open to some changes that will somewhat impact the tone of the clean channel.

1)  Change the values of the caps in the clean tone stack.
2)  Note that you may prefer the .02 for the mid cap or prefer an .047 or .05 for the mid cap.  Totally personal
     preference & they are just different, IMO.  I don't think one is better then the other.
3)  Change the .02 after the 2nd clean gain stage to .01
4)  Change the .02 coupling caps after the LTPI to .03.  This would beneficial IF you are using 5881/6L6's & perhaps
     not that useful if you are using 6V6's.  You can use Mallory .03 or parallel a Jupiter .01 on top of what you already
     have.
5)  Change the 10uf power tube cathode cap to 50uf or parallel a 50uf on top of the 10uf.
6)  You can change the V1-1 & V1-6 plate resistors to RN65 or 1w or 2w metal film resistors.

Study the schematic changes carefully.     With respect, Tubenit

Look over the schematic carefully.

[jinx1499]

This is all very helpful. Thank you for that. Any thoughts on the speaker combination? I feel as though that is playing a sizable role in the tone as well.

[tubenit]

IF it is NOT sounding good thru the wgs et65, …………….. then it's not the speaker, IMO.  That particular speaker is excellent for the OD channel & it is currently exactly the speaker I am using in my TBM.  It also sounds great in the OD with my Carolina Overdrive Special.  That is a favored speaker by some of the Dumble Cloners on TAG.

I have had success with tones I like using an Emminence Delta Pro 12A,   Emminence Cannabis Rex, Emminence Texas Heat (OK but not excellent) ,  Emminence Red, White and Blues and the WGS ET65 which has been my favorite of all of those for the TBM. 

With respect, Tubenit

[jinx1499]

Alright, that's what I thought. I will stick with the et65. What voltage should I use for the .0047 on the tone stack? I may have to order one. I presume that composition won't have an effect on tone, would that be correct?

[tubenit]

IF you have a .0047 rated for 400v then use that.  I don't think the type of cap will make a difference there?


IF you have a "bright cap" across the OD level pot, try unsoldering one leg of the cap rendering it useless. Does that improve anything?


With respect, Tubenit

[jinx1499]

I went ahead and ordered the .0047 400v cap to try, I will clip the current cap either tonight or tomorrow, test, and report back. No matter how small I try to make the pictures, they won't upload, so I made a  folder on my google drive for them . Hopefully it helps.

https://drive.google.com/drive/folders/1rIXLvrnY7e8p838hkB0ysC6UC28UtXgm?usp=sharing

[sluckey]

Right under the "Attach File" Browse box are the restrictions on file size.

[jinx1499]

I noticed that. This just seemed like the more expeditious way than resizing every picture.

[davidwpack]

I email them to meself from my phone. It automatically resizes them.

[jinx1499]

That's a really good idea! I'll save that for the next time. Thank you!

[tubenit]

After looking over the photos …………….  this is the best I can currently do in giving you a starting place DRAFT for a schematic and layout to make mods for the OD section.  Since your first post indicates you have a reasonably favorable view of the clean tone ………….  let's concentrate on the OD section alone (at first) & then you can decide IF you want other changes. 

Without the amp being in my possession,  I can not add the solid state reverb section into the schematic.  And for our purposes, it is probably not needed to tweak the OD area.

Consider this a DRAFT schematic and DRAFT layout that may contain some errors.  I can't accurately verify values of components from the photos.  So some of this presumes some integrity in the original builder's comment that he followed DaGeezer's original schematic.  (I am aware that the original builder did deviate in several places from the original schematic)

You will need to look the layout over carefully with the chassis in front of you.  AND compare the layout values with the values on the schematic

AFTER you have compared the drawn layout with the actual chassis layout,  post how well this matches up.  Look at component values between the two.  And look at the terminal/tag row # on the layout compared to chassis.  For example does layout row #8 match actual chassis layout row #8?

Once we can verify that this is a reasonable reference point for you to do mods on this amp, then we can improve the OD section and then consider other mods to clean channel or other tone mods also.

With respect, Tubenit

**  There was simply not room on the layout drawing to show the rock/jazz switch. However, there is a 2nd page
      in the ExpressSCH layout where I did draw this out for you, but it's not on the 1st page.

[tubenit]

J,

These are the OD mods that I think you should consider starting with:

1)  connect the OD tone control (hi-cut) to the drive pot instead of ratio pot
2)  change the .01 & .0047 caps to Orange Drop PS caps
3)  change the 220k & 150k resistors to Vishay-Dale RN65 resistors

& then …………

4)  let's add a smoothing cap from tag/terminal 10 to tag/terminal 9.  Use a 390p if you have one?  If you don't have
     one, then try anything from 220p to 500p  range.  What this does is add a smoothing cap from plate to cathode
     like is on the schematic.   (Now this presumes there is NO smoothing cap on that V2a triode section)

With respect, Tubenit

[jinx1499]

Status Report!

I went ahead and changed the OD portion with the OD PS caps as well as the Vishay RN65 resistors. I also popped two Vishay RN65 resistors in the clean section since I already had the iron warm. I changed the tone control to the drive pot as suggested as well. I ordered a 390p for smoothing so that's on it's way. Attached is a link of where we are at currently. This was recorded with a 62 reissue strat on the bridge with a set of Klein S7s. The speaker was a emi GB128.

https://drive.google.com/file/d/1jJYocaiSQifXfpLY1qzSExNRD4j9v0Lo/view?usp=sharing

This is nothing special as far as playing and what sounds like a child whiling in the background is, in fact, a child whining in the background...my toddler just had to be in the room but was mad that she had to be quiet. Sorry for the weirdness on that.

[tubenit]

So, do you think it improved the smoothness, fullness and/or lessened the harshness of the OD? 

No change,  worsened it, slight change, significant change, dramatic positive change ………………. ????  What's an honest review?

IF there is some slight or significant improvement, do you want to try a few more changes in the amp and continue?

If I am understanding the sound clip rightly,  you've done an excellent job contrasting the nice sounding clean going to a pretty overdrive OD channel.  You're covering a lot of tones with that. 

With respect, Tubenit

[jinx1499]

I think we're moving in the right direction. It's not as full or as balanced or as saturated as I'd like, but it's better than it was. I do think more changes are in order and plan to record a sample with each modification to track the progression. I'm game for any and all mods that get that OD right. I think the clean will always be some permutation of "awesome" but right now, I'm working with basically half an amp, since the OD isn't inspiring to me. We'll get there and I very much appreciate all the input of the great minds of this forum.

[tubenit]

These are ideas to consider and not something that I think you "should" do.  So much in tone is a personal preference.

There are some more caps in the clean and after the LTPI (phase invertor) that I think would benefit from changing into polyester caps.    You've already changed the V1 plate resistors so that's good.

The other thing is to consider changing the tone stack more towards a Dumblish topology and install a PAB (preamp boost) in place of the rock/jazz switch which some people report not using very much.

The last thing would be to consider increasing the value of the power tube cathode cap from 10uf to 47uf to 60uf range.   

Look at the phase 2 mods schematic and layout changes *attached

Look over the information and ponder it some.   With respect, Tubenit

[tubenit]

Hopefully, you can make sense of how to rewire the tone stack, eliminate the rock/jazz switch and add a PAB (preamp boost) from these illustrations. 

PLEASE feel free to post any questions, thoughts or comments.

Overall, I think you will find these mods to increase smoothness, lessen harshness particularly in the highs.

In case you have not already figured it out,  you'd use one row of the DPDT switch for the PAB which is shown as a SPDT switch.   (single pole double throw vs.  double pole double throw).

With respect, Tubenit

[jinx1499]

So it took a little while but here is the new and improved TMB. I've done everything in the above comments except the PAB and Master volume rewire but they're not off the table. Feedback is always welcome.

Clean channel with a bit of noodle'n
https://drive.google.com/file/d/11mrgZCt4PbgGLUHTgkBUWGHbal4L5kl2/view?usp=sharing

OD channel bridge then neck (just a little run so that all the different tone registers of the guitar can be heard)
https://drive.google.com/file/d/1C5Tjm6xl9i3TJzJcLrvdrXJ6_5siAKlq/view?usp=sharing

[jinx1499]

Apparently there is a little of a clean track that somehow got attached to the dirty. disregard that...or listen to it...either way.

[SILVERGUN]

I think that sounds great.
What do you think?

[tubenit]

The clean still sounds lovely & comparing this OD clip to the previous one, I hear a significant improvement.  This is smoother, IMO. It does not sound as "buzzy" as the previous one.

IF you listen to very many Dumble or Dumble clone clips, there is some "fuzz" tone in the OD when cranked. You can even hear this on some of Larry Carlton's CD's when his OD is engaged. 

So, in my way of thinking …….. you've moved this from a buzzy tone that wasn't as musical to an overdrive tone with some fuzz overtones that are musical.

I am curious how you have your OD pots set?   Using 1-10 as a reference,  I typically have my trim around 6-7,  my drive around 4-5, and my level  (called ratio on yours) at closer to 7 or higher. And it should be noted my drive pot is less then 100k now on my TBM.

IF you haven't done so already & you have time,  I'd be interested in hearing your OD with trim around 6, your drive around 4 and the ratio/level around 7-8.  My guess is you prefer more gain/OD then I do, but I'd love to have a comparison of smoothness with our respective OD tones with your drive pot dialed down some?

I think you have made substantial progress!  The PAB thing is simply personal taste.  I do think you might benefit from the master volume being rewired though?  I admire your perseverance!

With respect, Tubenit

[tubenit]

Regarding changing your master volume wiring so that the master volume is only on the clean channel  &  you're using the OD ratio pot for the master volume on the OD channel.

Looking at the picture of your chassis interior,  I am having trouble making out what is what????  Would have been nice if the original builder had given you detailed information with a schematic and layout regarding this set up.  His wiring may be creative and make sense and work OK …………….. but he sure left you in the dark with this set up and I think that's unfortunate.

One board looks like it has relay parts on it, but I am thinking it may also have parts to the reverb on it also?  No way for me to know from the picture alone and not having the amp in front of me?

What you are going to have to do is figure out 6 wires in your current wiring:   1)  wire from clean to relay,  2) wire from relay to OD,  3) wire from relay to ground,  4)  wire from OD back to relay,  5)  wire from relay to master volume,  6)  wire that jumps the clean to the remaining terminal on the relay.

IF you can post a drawing or photo showing what is going on,  I can help explain how to rewire the master volume so it's just on the clean channel.

With respect, Jeff

[tubenit]

What I thought was the relay is indeed a relay.    However, it looks like there may be some type of OpAmp on that perf board also & I'm not sure what that is for? 

The unknown part to the left (in the photo) of the HOF reverb boards may be some type of power supply either for the relay or for the board???   

with respect, Tubenit

[jinx1499]

Seems like we're at a bit of a dead end here. I don't think that, between the design of the amp by the original builder, my inexperience, and the distance between Tubenit, that there can really be any resolution in that department. But! Considering the development and progression of the amp, I'm alright with it. Thanks to everyone who has weighed in and given input. It really did help.