Non-HRM with toothy cleans

[toml]

For those interested, I was looking to reduce headroom and get a tone that broke up on clean at more reasonable volumes. I also wanted a more toothy, clean that suits a modern country/blues style of playing.

In another thread about the BM PI, Heisthl recommended that I try modifying V1A. The recommendation was spot on.

The setup that I settled on is as follows.
V1A - 100k, 1.5k 33uf (was 220k, 3.3k 5uf)
V1B - 150k, 2.2k 10uf (was 150k, 2.2k 5uf)
V2A - 220k, 3.3k 5uf
V2B - 150k, 2.2uf 5uf

My tone stack is a sort of hack. I have a 330pf/0.002 treble network
a 100k mid pot and switch to alter the mid cap between 0.01uf and 0.05uf.

The bass pot is 500k and includes the "bass mod" per the dLite (a switch that shorts pins 2 and 3)

Bluesmaster PI

Heritage G12-65 speaker in a combo and Scumback H75 in a 1x12 extension.

On my strat, I set the bass mod ON, mid to 0.05
On the clean channel, I get a really nice blues breakup with the volume around 1-2 o'clock. It grinds nicely but cleans up exceptionally well with a slight roll back of the volume knob.

Engaging PAB and the tone can grind even more - perfect for my style of playing.

The OD does not appear to have changed in any significant way, and regardless, the quality of the tone is still right on the mark. I did dial my od trimmer back to around 10:30-11:00 oclock.

Tele, I turn bass mod OFF, mid to 0.01 - This resembles a skyliner with the exception of the mid control. (I left the mids at 100k because when I auditioned the skyliner, I never turned up the mids very much anyways).

With the guitar volume up, I get a sort of greasy, hair on my cleans, great for country solos. The OD sounds great to my ears as well.

I am going to gig test this set up for a couple of shows and see how it goes. Preliminarily, its a keeper.

Thanks to everyone for the advice they share here.

Tom

[greiswig]

Really interesting. I wonder how much it has to do with the cathode bypass caps? My setup currently has 100/1.5/15uF on V1a, 120/1.8/6.8uF on V1b. It just doesn't ever get un-clean. It is a very nice clean, though.

[toml]

greiswig:

That's an interesting observation.

I am just wagering a guess here, but my initial impressions tell me that three important ingredients to the tone I am achieving are the 100k/1.5k on V1A, the bluesmaster PI, and pushing the clean volume and the master volume enough to get the amp cookin.

I sort of set the bypass caps to taste. I auditioned 10uf on V1A and the grind was there on the cleans. I simply preferred the 33uf (I did not try 20-25 as the 33 was all that I had on hand.)

I believe that I perceived 33uf as adding a bit more fullness to the low end. I have a bass rolloff network at the entrance of the OD, so the thicker cleans do not mud out the OD.

From there, to my ears, the 0.05uf mid cap really brings the strat tone out. That said, I still get a decent grinding tone from my strat even with the mid cap at 0.01uf.

Didn't you say that you converted back to the standard PI? Where are you running your master?

Tom

[greiswig]

Yes, I'm running the standard PI. I had also wondered what the different PI might do, but the implication of the PI changing the clean grind is that it is the PI generating that grind, not V1. If that were the case, I wouldn't expect changes to V1a to have the effect that you and heisthl described.

I have a newer Tung Sol AX7 in V1, and they are quite gainy. Would a tube with less gain break up sooner than one with more?

Another thing I noticed was that there seems to be less gain on the clean channel with the 100k front end: I think I have to turn the volume up higher for an equivalent loudness. But IIRC, that's to be expected when lowering the plate resistors.

I also have an overdrive high-pass filter setup, so I could set up the clean stage to have lower extension via the cathode bypass caps.

Typically I run the master only about 10-12:00. Halfway up. The clean volume seems to find a balance at about 2:00 or so.

[toml]

greiswig:

I did some more experimenting with my new configuration. With the volume at 3:00 and the master between 1-2:00, I can get a grinding clean on a strat with Lindy Fralin vintage hots. Perfect for blues and country. That's a little hotter than the settings you suggested. I would not hesitate to crank that amp up!

As another experiment, I tried several different output tubes.

Tung Sol 5881s were my least favorite. The tone was thin and unremarkable. I am unsure whether these tubes will open up with time or not. For now, they are going back in their box.

JJ 6L6 - These tubes leant an immediate improvement in the low end. The mids were also improved over the 5881s that I tried. However, I felt the top end was missing some zing.

Svetlana EL34. To my ears, this was the winning tube by a significant measure. The low end is authoritative, the mids are rich and the top end is clear and detailed. I am going to gig test these tubes this weekend.

Keep us posted on your progress.


Tom

[greiswig]

Yes, I'm running the standard PI. I had also wondered what the different PI might do, but the implication of the PI changing the clean grind is that it is the PI generating that grind, not V1. If that were the case, I wouldn't expect changes to V1a to have the effect that you and heisthl described.

Thanks for the update. Trust me - cranking the volume is not the issue. It just isn't there, for some reason, on my build. I wish heisthl or someone else would weigh in on what I wrote above. I wonder if the PI is what is generating your OD?

[greiswig]

Nobody wants to weigh in with an educated guess?

I'm still wondering what the clean channel breakup difference is between my non-HRM/standard PI amp with 100k/120k V1 values and Tom's non-HRM/Bluesmaster PI with 100k/150k V1 values. Why doesn't mine get to that breakup point?
- is it the PI that is actually breaking up in Tom's?
- what else might cause this difference?

[toml]

greiswig:

I should have some time after this weekend to record some clips. It might help everyone to understand what I am calling "toothy/greasy/gritty" on my clean channel.

I can say that I am enjoying this configuration more and more, esp. since installing the EL34s.

Tom

[greiswig]

greiswig:

I should have some time after this weekend to record some clips. It might help everyone to understand what I am calling "toothy/greasy/gritty" on my clean channel.

I can say that I am enjoying this configuration more and more, esp. since installing the EL34s.

Tom

That definitely could be the whole issue here: I interpret "toothy" as being not quite clean, but not very overdriven either. Back off on the pick or guitar volume and it really *is* clean, but lean into it and you're getting that bluesy Fendery breakup.

[greiswig]

Tom, what valve are you using in V1?

[toml]

greiswig:

Our definitions of toothy, grinding clean are about the same.

As far as tubes, I have tried in the V1 spot, EH, Tung Sol, RCA, JJ, Westinghouse, EI Elites. I think that's it. The only tube that I did not like was the EI elite. That tube was rich sounding but too microphonic to be usable.

All of the above tubes were able to elicit the grind that I was after, just in different flavors.

I will try to get some clips up after the weekend.

[greiswig]

greiswig:

Our definitions of toothy, grinding clean are about the same.

As far as tubes, I have tried in the V1 spot, EH, Tung Sol, RCA, JJ, Westinghouse, EI Elites. I think that's it. The only tube that I did not like was the EI elite. That tube was rich sounding but too microphonic to be usable.

All of the above tubes were able to elicit the grind that I was after, just in different flavors.

I will try to get some clips up after the weekend.

Hey, Toml,

I found I was able to elicit a nice grind with the Volume at 3:00 with my setup. All I had to do was put a speaker attenuator on the amp, crank the MV to a little over 12:00, and there it was. So....

Without the speaker attenuator in there, this would be real loud in my listening environment. Where are your controls set when you're getting this?

The implication in my case is that the PI is what is grinding, not V1...unless I'm not understanding something. If that's the case, then I could have gotten this flavor with the previous cathode/plate values on V1a.

[toml]

Without the speaker attenuator in there, this would be real loud in my listening environment. Where are your controls set when you're getting this?

Strat and tele - volume between 1:00 - 3:00 to taste, MV around 12:00-1:00.

I just tried my amp with a Les Paul. With humbuckers, this combination easily gets gritty on clean as early as 11:00 on volume. That said, I can back the volume to clean right up. Its pretty nice to my ears.

I am having a pretty hectic week. Once things slow down, I will work on some clips.

[jzucker]

clips? I have no problems getting "toothy" cleans with mine using the updated layout I did based on Gil Ayan's and Scott Lerner's tweaks.

My problem is that the clean is peaky. This is true of the Fuchs as well so I suspect it's inherent to the design. Two rock has a sweeter clean but their OD sounds more flabby so maybe it's an inherent compromise...