One of the schematics around here has a 1uf bypass cap on it.
I can't remember what stage it's on.
But I think I may have one in my amp.
It was getting woofy at volume so I think I stuck that in there.
Been a while so I can't remember exactly I put it.
Nothing is etched in stone.
I'm sure there are amps that HAD modded for the player that we haven't been privy to.
It doesn't really matter what somebody puts in their amp as long as they are happy with the results.
dogears wrote:Actually, I have never seen 1uf on CL2. I have seen many many real ones with .05uf on CL2 in conjunction with either 4.7uf, or as high as 25uf if 100K plates are used.
To reiterate, amps with .05uf typically had 5uf bypass. Sounds WAY better to me than the 1uf which I have always disliked in any context.
dogears wrote:The higher plate amps, IMHO, do not have a .05uf. The one amp I saw had a .01uf there!! The HRM has it, but that is a different circuit. The Hybrid A amp had it, but with a 1uf bypass! I know of no 220/150 non-HRM amp that has a .05uf on CL2 with a 4.7uf bypass.
Please don't feel offended. I'm more than grateful that you share your observations here!
Structo wrote:One of the schematics around here has a 1uf bypass cap on it.
I can't remember what stage it's on.
But I think I may have one in my amp.
It was getting woofy at volume so I think I stuck that in there.
If your amp gets woofy at higher volumes, maybe you should consider increasing the uF in the first stage (B1) of your amps power supply, instead?? Upping the two 100uF's to 150uf's in my 50w amp, gave a much more firm bottom end at higher volume.
Thanks for finding that post, at least I don't have to doubt my sanity any longer!
In the post dogears does state that he believes that the lower CL2 works with 4.7uf Ck, whereas in response to my earlier post he states that he has never seen it in a real deal. Considering the age of the post and the fact that dogears is probably a bit of a Dumble tart (we probably all are!- no offence intended) when an opportunity to get inside one presents itself, I suspect that a great deal of research has happened since then.
Joking aside, making this change in my amp cured the 'woofyness' and transfomed my amp into something that worked for me, which is the great advantage of DIY.
Guitarman18 wrote: I suspect that a great deal of research has happened since then.
That's of course the easiest explanation.
Didn't realise that the older post was that old. Should have thought of this myself
Also I should have read this thread more thoroughly. For some reason I didn't see that you already have asked more or less the same question
In my defence: I got a cold and actually should stay in bed instead of sitting at the computer and browsing through this forum...
That was an OLD post! Since then alot has been learned. There are plently of .05uf CL2 amps with high plates and 4.7uf. Although Hybrid A shows a 1uf on the bypass, I have not seen any with my own eyes. Plus, I do not like the tone of that at all. Two Rock copied that in the Sig V1 for years..... Not a fan of removing bass that way. Gets rid of the texture.
markusw wrote:
dogears wrote:Actually, I have never seen 1uf on CL2. I have seen many many real ones with .05uf on CL2 in conjunction with either 4.7uf, or as high as 25uf if 100K plates are used.
To reiterate, amps with .05uf typically had 5uf bypass. Sounds WAY better to me than the 1uf which I have always disliked in any context.
dogears wrote:The higher plate amps, IMHO, do not have a .05uf. The one amp I saw had a .01uf there!! The HRM has it, but that is a different circuit. The Hybrid A amp had it, but with a 1uf bypass! I know of no 220/150 non-HRM amp that has a .05uf on CL2 with a 4.7uf bypass.
Please don't feel offended. I'm more than grateful that you share your observations here!
dogears wrote:That was an OLD post! Since then alot has been learned. There are plently of .05uf CL2 amps with high plates and 4.7uf. Although Hybrid A shows a 1uf on the bypass, I have not seen any with my own eyes. Plus, I do not like the tone of that at all. Two Rock copied that in the Sig V1 for years..... Not a fan of removing bass that way. Gets rid of the texture.
Structo wrote:One of the schematics around here has a 1uf bypass cap on it.
I can't remember what stage it's on.
But I think I may have one in my amp.
It was getting woofy at volume so I think I stuck that in there.
If your amp gets woofy at higher volumes, maybe you should consider increasing the uF in the first stage (B1) of your amps power supply, instead?? Upping the two 100uF's to 150uf's in my 50w amp, gave a much more firm bottom end at higher volume.
The woofy bass was before I tried a couple other things as well.
Yes when I re-capped my amp a few months back with new F & T's, I took the large 100uf 350v caps I had taken out and piggy backed them on the new 100uf caps making the B+ filter 200uf.
Didn't really change the bass tone as much as tighten it up in the bottom end.
I wish I could do a quick switch a roo, with those two values to compare the two first stage filtering quickly.
But for now I think I like it and will leave it as is.
After reading through this thread and that older one, I think I put the 1uf bypass on OD2.
There was a 1uf cap specified on OD2 one of the BM schematics, mdroberts version, I think. I tried those values spec'd in that schemo (plates and bypass caps) in my 60 watt and really did not like it. Went back to different plate values and 5uf accross for bypass caps.
Be careful when looking at the schematics. I am a huge believer in building the real deal circuits and then tweaking. Fact is that "maybe" there are one or two Dumbles, "maybe", with a 1uf on CL2.
I have never seen it. It may exist. But I see no reason as it doesn't ever sound as good to me.
I can say, that mroberts made that change on his own and nobody has ever seen 1uf for real in a Dumble BM.
Many schematics on here have alterations to values that just have never been seen in the real world.
zimm wrote:There was a 1uf cap specified on OD2 one of the BM schematics, mdroberts version, I think. I tried those values spec'd in that schemo (plates and bypass caps) in my 60 watt and really did not like it. Went back to different plate values and 5uf accross for bypass caps.
My change of 1uF on OD2 was the result of tweaking... specifically to deal with a bad double-stop tone produced by the distortion (and aggravated by a particular guitar & pickup combo).
As Scott is aware, I have tweaked the build further since the 'final' schematic, but left the schematic as a good, stable 'snap-shot' of the build. I think everybody should be aware that the amp performance is the result of a 'whole' package and you should be careful to avoid picking up one change when the tone is a combination of all the various sub-circuits/eq/tubes/etc.
All that being said, I really believe in having a reference schematic for at least one real example of a Bluesmaster, something I don't believe we have publicly available yet... I would love to start a new schematic thread with changes to document a particular BM100... e.g. BM100W #xxx !!!
I'll keep asking/offering and perhaps one day we'll get there... perhaps after the commercial market moves on to the next big thing.
dogears wrote:Be careful when looking at the schematics. I am a huge believer in building the real deal circuits and then tweaking. Fact is that "maybe" there are one or two Dumbles, "maybe", with a 1uf on CL2.
I have never seen it. It may exist. But I see no reason as it doesn't ever sound as good to me.
I can say, that mroberts made that change on his own and nobody has ever seen 1uf for real in a Dumble BM.
Many schematics on here have alterations to values that just have never been seen in the real world.
zimm wrote:There was a 1uf cap specified on OD2 one of the BM schematics, mdroberts version, I think. I tried those values spec'd in that schemo (plates and bypass caps) in my 60 watt and really did not like it. Went back to different plate values and 5uf accross for bypass caps.
dogears wrote:I suspect that Peter doesn't know that Skyline refers to the clean channel tonestack. I think he thinks it means HRM.
I guess it is a high plate 220/150 Skyline non HRM. Just like almost all the other non Music Man non HRM amps of that era.
Secondly, he is using midboost in conjunction with the PAB. This is why it sounds full and good in jazz mode and at low master settings.
Good point. I didn't consider that he could be wrong when describing his own amp. I also noticed no Deep switch which made me think it might be a non-Skyliner stack. I know this has been discussed before, but what do you listen for to distinguish a low plate from a high plate amp? I tend to think the clean sound on low plate amps is sweeter, especially when pushed slightly.
Whit, my hi plate amp is just oozing with tone, don`t let it scare ya!
dogears wrote:I suspect that Peter doesn't know that Skyline refers to the clean channel tonestack. I think he thinks it means HRM.
I guess it is a high plate 220/150 Skyline non HRM. Just like almost all the other non Music Man non HRM amps of that era.
Secondly, he is using midboost in conjunction with the PAB. This is why it sounds full and good in jazz mode and at low master settings.
Good point. I didn't consider that he could be wrong when describing his own amp. I also noticed no Deep switch which made me think it might be a non-Skyliner stack. I know this has been discussed before, but what do you listen for to distinguish a low plate from a high plate amp? I tend to think the clean sound on low plate amps is sweeter, especially when pushed slightly.
Whit, my hi plate amp is just oozing with tone, don`t let it scare ya!
jp
Well, I was sharp enough to order all the values to go to high plate if i don't dig the low plate one. Lets see, to put this on a switch you would need a DP8T switch right (that's double pole, 8 throw)?
