Interesting findings re: caps and HRM

[Structo]

I looked up the WIMA caps.

It seems there is the MKS 2 Series and the MKP 2 Series.

The MKS 2 being the polyester and the MKP being the polypropylene.

Which style do you like?

BOB, On the Xicon MPP caps, are you using the 630v ones?

So you replaced all the film caps on the PI with the Xicon MPP caps?

3 x .1uf and the one .02uf?

I found after I switched to 2 x EVM 12L Classics, that the bottom really firmed up. Man I love those speakers.

[Bob-I]

BOB, On the Xicon MPP caps, are you using the 630v ones?

So you replaced all the film caps on the PI with the Xicon MPP caps?

3 x .1uf and the one .02uf?

Yes, yes and yes

I found after I switched to 2 x EVM 12L Classics, that the bottom really firmed up. Man I love those speakers.

Gotta love a firm bottom.

[Structo]

I may have to try those, my local parts house carries those.

[Bob-I]

I also replaced the bright switch with a 3 way, middle off, down 120pF and up another 120pF in series with the first for 240pF. Very cool.

Must be the new math - I can't get 240pf when I series 2 120pf caps.

Sorry Parallel.

[FuzzFaceBuilder]

Same here!! They are kind of cool in the clean stack .1 Bass cap only.. To me kind of softens the bass...
EJ does this in his Twin's.

Did anyone else notice that the AC cable is 2-conductor?! I'll have to try that with my reissue twin! Hahahaha! That's where the tone is, you know! j/k!

Also the silver mica treble cap on the normal channel is cool too...

[FuzzFaceBuilder]

Double post!

[dogears]

Bob, I am curious as to your comment regarding the HRM bass trimmer. On the HRM builds I have either been involved in or checked out, the bass trimmer has a big effect all the way up to about 600k or so. Many of these amps sound best (IMO) with the bass trimmer set between 350k and 550k, depending on axe and other variables. I can say with certainty that you totally hear the bass control effect as you sweep it. I suppose if you dime the mid trimmer then that would effect the bass trimmer setting, but in the HRM Dumbles I have seen this was not the case, as it is not the case in any HRM build I have been involved with, inclucing what I have seen in the Bludos as well. You actually lose high end cut if you turn the bass down too low. I would imagine that if you have incorporated a mega boost, this would change things as well. But, in a standard Skyline boost, something must be wrong if your control has little effect past 50K.

This is pertaining to NON-bluesmaster HRM. The Bluesmaster bass trimmer is acting much more like a switch. 250K trimmer seems appropriate.

[talbany]

Scott
Long time no hear!!.. Hope you are well and keep posting.. Your input here is invaluable!!! Take Care..



Tony VVT

[Bob-I]

Bob, I am curious as to your comment regarding the HRM bass trimmer. On the HRM builds I have either been involved in or checked out, the bass trimmer has a big effect all the way up to about 600k or so. Many of these amps sound best (IMO) with the bass trimmer set between 350k and 550k, depending on axe and other variables. I can say with certainty that you totally hear the bass control effect as you sweep it. I suppose if you dime the mid trimmer then that would effect the bass trimmer setting, but in the HRM Dumbles I have seen this was not the case, as it is not the case in any HRM build I have been involved with, inclucing what I have seen in the Bludos as well. You actually lose high end cut if you turn the bass down too low. I would imagine that if you have incorporated a mega boost, this would change things as well. But, in a standard Skyline boost, something must be wrong if your control has little effect past 50K.

This is pertaining to NON-bluesmaster HRM. The Bluesmaster bass trimmer is acting much more like a switch. 250K trimmer seems appropriate.

I have not found the same. All of my HRM amps act the same, bass trimmer above about 100K makes no difference at all. Below 100K little changes make a big difference. This is non-Bluesmaster.

[dogears]

We should get together and play with some amps.....

Bob, I am curious as to your comment regarding the HRM bass trimmer. On the HRM builds I have either been involved in or checked out, the bass trimmer has a big effect all the way up to about 600k or so. Many of these amps sound best (IMO) with the bass trimmer set between 350k and 550k, depending on axe and other variables. I can say with certainty that you totally hear the bass control effect as you sweep it. I suppose if you dime the mid trimmer then that would effect the bass trimmer setting, but in the HRM Dumbles I have seen this was not the case, as it is not the case in any HRM build I have been involved with, inclucing what I have seen in the Bludos as well. You actually lose high end cut if you turn the bass down too low. I would imagine that if you have incorporated a mega boost, this would change things as well. But, in a standard Skyline boost, something must be wrong if your control has little effect past 50K.

This is pertaining to NON-bluesmaster HRM. The Bluesmaster bass trimmer is acting much more like a switch. 250K trimmer seems appropriate.

I have not found the same. All of my HRM amps act the same, bass trimmer above about 100K makes no difference at all. Below 100K little changes make a big difference. This is non-Bluesmaster.

[ayan]

Bob, I am curious as to your comment regarding the HRM bass trimmer. On the HRM builds I have either been involved in or checked out, the bass trimmer has a big effect all the way up to about 600k or so. Many of these amps sound best (IMO) with the bass trimmer set between 350k and 550k, depending on axe and other variables. I can say with certainty that you totally hear the bass control effect as you sweep it. I suppose if you dime the mid trimmer then that would effect the bass trimmer setting, but in the HRM Dumbles I have seen this was not the case, as it is not the case in any HRM build I have been involved with, inclucing what I have seen in the Bludos as well. You actually lose high end cut if you turn the bass down too low. I would imagine that if you have incorporated a mega boost, this would change things as well. But, in a standard Skyline boost, something must be wrong if your control has little effect past 50K.

This is pertaining to NON-bluesmaster HRM. The Bluesmaster bass trimmer is acting much more like a switch. 250K trimmer seems appropriate.

I think you're both right, and that the effect continues as the bass trimmer is dialed up while the bulk og the change happens all at once. According to simulation results -- not mine, I mean Duncan's tool with Fender tone stack but Marshall values -- going from a setting of 0 to 100K boosts the signal by 9-10dB at 100 Hz. Going from 100 Hz all the way to 1 Meg only boosts an additional 2-3dB. So a lot of change in the first tiny turn, and then much less change over a long turn. That's the on-off switch we all talk about.

Then there is what you specifically address, Scott, and that is that the TS is quite interactive. If folks use a speaker that rolls of the highs, like Celestion 65s, they will turn the treble up and in doing so, they will turn the bass up to compensate. However, if one uses an EV and needs to keep the treble set low, the bass can become overwhelming real quickly. So with the EV speakers, to me the key is to be able to keep the treble up in the little TS (things don't sound "right" if the thing is less than halfway up) and pick another spot in the signal chain where emphasis on highs can be relaxed a bit.

Gil

[Bob-I]

We should get together and play with some amps.....

Great idea.... (Bob patiently waits for Scott's invitation...... )

[Bob-I]

Bob, I am curious as to your comment regarding the HRM bass trimmer. On the HRM builds I have either been involved in or checked out, the bass trimmer has a big effect all the way up to about 600k or so. Many of these amps sound best (IMO) with the bass trimmer set between 350k and 550k, depending on axe and other variables. I can say with certainty that you totally hear the bass control effect as you sweep it. I suppose if you dime the mid trimmer then that would effect the bass trimmer setting, but in the HRM Dumbles I have seen this was not the case, as it is not the case in any HRM build I have been involved with, inclucing what I have seen in the Bludos as well. You actually lose high end cut if you turn the bass down too low. I would imagine that if you have incorporated a mega boost, this would change things as well. But, in a standard Skyline boost, something must be wrong if your control has little effect past 50K.

This is pertaining to NON-bluesmaster HRM. The Bluesmaster bass trimmer is acting much more like a switch. 250K trimmer seems appropriate.

I think you're both right, and that the effect continues as the bass trimmer is dialed up while the bulk og the change happens all at once. According to simulation results -- not mine, I mean Duncan's tool with Fender tone stack but Marshall values -- going from a setting of 0 to 100K boosts the signal by 9-10dB at 100 Hz. Going from 100 Hz all the way to 1 Meg only boosts an additional 2-3dB. So a lot of change in the first tiny turn, and then much less change over a long turn. That's the on-off switch we all talk about.

Then there is what you specifically address, Scott, and that is that the TS is quite interactive. If folks use a speaker that rolls of the highs, like Celestion 65s, they will turn the treble up and in doing so, they will turn the bass up to compensate. However, if one uses an EV and needs to keep the treble set low, the bass can become overwhelming real quickly. So with the EV speakers, to me the key is to be able to keep the treble up in the little TS (things don't sound "right" if the thing is less than halfway up) and pick another spot in the signal chain where emphasis on highs can be relaxed a bit.

Gil

Thx Gil, that makes a lot of since. I use an EVM12L in a thiele ported cab, in addition Scott tends to like his tone darker than I do, personal preference and music styles.

[talbany]

We get the same result...Bass comes in quickly on a 1m or 500k trimmer..With the 1M after 500k 1/2 way up pretty much loses it's range...Depending on the amp a 56K slope in the od can help with it being a bit on the edgie side if you are using a bright speaker...



Tony VVT

[ayan]

We get the same result...Bass comes in quickly on a 1m or 500k trimmer..With the 1M after 500k 1/2 way up pretty much loses it's range...Depending on the amp a 56K slope in the od can help with it being a bit on the edgie side if you are using a bright speaker...



Tony VVT

You can dump highs to ground at the input of the overdrive master volume, which is a 1K pot. Try anywhere between 100pF and 250pF... The sound will get sqashed if the cap is too large for your amp, so you need to experiment. However, with the right size cap, you will be able to open the treble trimmer on the HRM and still get a good sound with EVM speakers. THAT's when the entire amp will begin to make more sense. Of course, if you use other than EVM speakers in the first place, you may save yourself this additional step.

Gil