D'lite to Bluesmaster migration testing

[deiseldave]

Hey Guys - I'm looking at trying the Bluesmaster tweaks that Smokebreak recommended here https://tubeamparchive.com/viewtopic.ph ... 6&start=30 , and wondering how invasive I need to be, just to experiment.
For example, how critical is it to replace the .1uf caps off the PI plates with .02uf? Also, same question with changing 3k3 6V6 grid resistors with 5k1?
As far as paralleling stuff in, I'm also curious about how critical some of these values are, and what is "close enough". For example, the 511R in the BM PI. With Dlite, I currently have an 820R in place, so if I parallel in a 1k5, I get 530R. Is that close enough for tone test? Then, if I like it, order resistors closer to actual value?
Having never heard a Bluesmaster, I'm not sure if it is for me. But, Smokebreak has given me great advice in the past, so I want to try it. However, would like to keep the path back to D'lite specs clear, in case it is not for me.
Thanks - Dave

[ToneMerc]

Hey Guys - I'm looking at trying the Bluesmaster tweaks that Smokebreak recommended here https://tubeamparchive.com/viewtopic.ph ... 6&start=30 , and wondering how invasive I need to be, just to experiment.
For example, how critical is it to replace the .1uf caps off the PI plates with .02uf? Also, same question with changing 3k3 6V6 grid resistors with 5k1?
As far as paralleling stuff in, I'm also curious about how critical some of these values are, and what is "close enough". For example, the 511R in the BM PI. With Dlite, I currently have an 820R in place, so if I parallel in a 1k5, I get 530R. Is that close enough for tone test? Then, if I like it, order resistors closer to actual value?
Having never heard a Bluesmaster, I'm not sure if it is for me. But, Smokebreak has given me great advice in the past, so I want to try it. However, would like to keep the path back to D'lite specs clear, in case it is not for me.
Thanks - Dave

The least laborious thing to is to just change the PI and yes I would decrease the couplers to at least .047, if not .02. The BM is the some of the entire amp not just the PI values. Since you are not running EL34's you can leave the grid stoppers at 1.5K.

Brownnote Blue Monkey for reference

https://tubeamparchive.com/download/file.php?id=39516

TM

[martin manning]

Plenty close enough on the bias resistor, and the grid stoppers won't be noticeable, but the coupling caps are different by a factor of five. That means the corner frequency will move up five octaves, from ~7Hz to ~36Hz. You'll have t swap those out to get the feel of the reduction in bottom end.

[deiseldave]

The least laborious thing to is to just change the PI and yes I would decrease the couplers to at least .047, if not .02. The BM is the some of the entire amp not just the PI values. Since you are not running EL34's you can leave the grid stoppers at 1.5K.

Brownnote Blue Monkey for reference

https://tubeamparchive.com/download/file.php?id=39516

TM

TM - I understand, and was just wanting to hear the effects of the different changes, as I migrate that way. Thanks for the layout link, and help.

Plenty close enough on the bias resistor, and the grid stoppers won't be noticeable, but the coupling caps are different by a factor of five. That means the corner frequency will move up five octaves, from ~7Hz to ~36Hz. You'll have t swap those out to get the feel of the reduction in bottom end.

Thanks Martin.

[Smokebreak]

Hey Dave, I'm curious how you are getting along with the BM changes. I had an old customer get in touch the other day. I had done just a straight up Deluxe reverb build for him, and he wanted me to mod the Norm channel. I put in the high plates and Marshall tonestack a la BM specs and he's in love. Most folks are, when you add mids to the Fender cleans

[norburybrook]

The clean of the BM is really nice, probably the best of any ODS type Dumble.



Marcus

[deiseldave]

Hey Dave, I'm curious how you are getting along with the BM changes. I had an old customer get in touch the other day. I had done just a straight up Deluxe reverb build for him, and he wanted me to mod the Norm channel. I put in the high plates and Marshall tonestack a la BM specs and he's in love. Most folks are, when you add mids to the Fender cleans

Thanks for the follow up, Smokebreak. After studying the changes, I determined I didn't have some parts needed to parallel in. So, I ordered parts. Should be here Friday.
I am in the process of converting my Plexi-6V6 to a "Neil" 2 in 1 1959 Bright/2204. The Plexi6V6 had some issues that were largely "first time builder" mistakes. I decided to clean it up, and use the extra relay kit I got from Dave at Colossal.
After that, I am converting the D'lite to Bluesmaster on faith. Everything you (and others) have described is exactly what I'm looking for. Besides, this is a learning process anyway. If it doesn't work out for me, then I'll have learned that.
I will let you know either way when I'm done, and post some clips.
Thanks again. Dave

[deiseldave]

The clean of the BM is really nice, probably the best of any ODS type Dumble.



Marcus

Getting stoked to make changes. Can't wait to hear.

[Smokebreak]

Right on man, have fun.

[deiseldave]

Right on man, have fun.

Changed my mind. I'm pushing out the Plexi-6v6 to Plexi/JCM800 mod for another week, and doing the D'lite to Bluesmaster mod this weekend.
I noticed that the D'lite scheme I followed showed input jack going to V1 pin 2, and Bluesmaster shows V1 pin 7. I've done some reading that V1 pin 7 is the preferred input.
Is there an appreciable difference in noise when using Pin 7 for the input jack side? Also, would best practices set up all dual triodes (V2, V3, etc) this way? Where the preamp section closest to the input would go to pins 6, 7, 8, and the side closest to outpot go to 1, 2, 3?
Thanks - Dave

[Smokebreak]

I remember a discussion about something similar, but if I think about it logically, I can't think of any reason why pin 7 would produce less noise than pin 2(assuming both triodes are exactly the same). You'll notice that in the BM layout the socket is turned around 180deg from the "normal" way, so yes, it makes sense to wire the input to pin 7, if you have your socket oriented that way. The important thing is that the signal flows in a linear fashion, as far as the layout goes. Right to left, or left to right. Don't go doublebacking on yourself. That just ends up putting in-phase signals closer to one another, which can lead to problems.

[deiseldave]

I remember a discussion about something similar, but if I think about it logically, I can't think of any reason why pin 7 would produce less noise than pin 2(assuming both triodes are exactly the same). You'll notice that in the BM layout the socket is turned around 180deg from the "normal" way, so yes, it makes sense to wire the input to pin 7, if you have your socket oriented that way. The important thing is that the signal flows in a linear fashion, as far as the layout goes. Right to left, or left to right. Don't go doublebacking on yourself. That just ends up putting in-phase signals closer to one another, which can lead to problems.

Thanks Smokebreak. I'm not sure I fully understand what signals are "in phase" and what are out. I am aware of the 90 degree shift that happens between input and output of the stage. So, that would make me think cathode and grid are in phase, and plate would be 90 degrees out? Is my thinking correct?
I guess the reason why I'm interested in this, is that I have been reading Merlin's preamp book, and it shows an example of grid, cathode, and plate wires twisted together, and suggests that as a good thing to do..
To me, it is pretty obvious to not run signal parallel with heaters or other AC power. But I'm a little shaky on the "do's and don'ts" of which wires to mingle or separate.
My gut tells me to twist cathode and plate, and separate grid. However, that may be completely incorrect.
Nevertheless, the D'lite OD channel was a little noisier than I would like, so I am going to reverse V1, and see if using 6, 7, 8 as input makes a difference.
Actually, I think it was also one of Merlin's posts somewhere that suggested there was a noise difference between the two triodes due to the way the tube is constructed.
Thanks again.

[Smokebreak]

If you can find that topic you should post it. I'd be interested to read it again.
What i should say is that the signal gets inverted every time it passes through a gain stage, 180 degrees. So you try and keep the signal coming off the first stage away from the signal coming off the third stage, say. It's easy for the 3rd stage signal to impress upon the 1st stage low level signal, and can cause oscillations. But I misspoke, as if you oriented all of your sockets to use V_b first, you wouldn't have that problem. If you just reoriented the first one, you might.
As far as lead dress goes, personally I just try and give the grid wires some space. While there are other steadfast "rules", I find this one the most useful, practically speaking.
If you wanna twist the cathodes and plates, no harm., and Dumble certainly kept them close, some would say for a reason.
I would guess, if you do reorient the sockets, and the amp is quieter, that it's only a result of the change in the sense that the V1b triode was quieter than the V1a triode.
To me the number #1 cause of noise is tubes. Of course grounding is important but for noise concerns it's all about the tubes IMO. Mojo is another story

[deiseldave]

If you can find that topic you should post it. I'd be interested to read it again.

This is where I read it, initially: http://www.ax84.com/bbs/dm.php?thread=334322
Then, when looking for it, I also found this (see remark on page 1): http://www.mif.pg.gda.pl/homepages/fran ... /ECC83.pdf

[Structo]

The confusing thing is some manufacturers wired the the V1b side to pins 1,2,3.


While others seem to have the first triode on 6,7,8.