The Bluesmaster

[ayan]

Thought I'd post about some findings with the BM, with hopes that it might help a few folks. Recently, as Chris Sanford was visiting, we decided to try the BM with my Dumble approved 2x12 cabinet loaded with two Eminence speakers, their version of the Classic Lead 80. The amp sounded much better than with the EVM 12L 1x12 cabinet I usually play through and I thought that, once again, there could be some potential there. So I did try the amp at a gig with the EVM and it was just not happening.

Yesterday and today I was messing around with it and found what may be a solution to make the amp morre EVM friendly. First of all, I consulted with Scott as for the "ultimate settings" for the amp and backed off the pre OD trimmer to 25K to ground. Any higher than that and dialing in a good sound gets complicated real quickly. Not that therer wouldn't be any good sounds there, but it becomes a pretty difficult balancing act. Also, I dialed in the the HRM as follows: Middle = 6.5K to ground, Bass = 40K to gound, and Treble = 115K to gorund. I had the HRM dialed in basically like that, but with the treble lower to avoice the ice pick in the ears effect. However, dialing the Treble low is not the solution here, as Brandon had mentioned to me in the past as well.

I went full steam and rermoved the 330pF caps at OD1 and OD2 as well, and although that made the amp brighter, it was not necessarily a bad brighter, if that makes any sense. With these settings, the amp sounded terrific with the 2x12, but bright in a bad way the EVM 12L. So, I started trying different caps bypassing the OD Master volume and found that a 100pF cap (fully bypassing the OD Master) makes things workable with the EV. I am going to take the amp, as is, to a gig on Friday and find out how it works for real.

One other thing I will mention is that for amps with a Heyboer multi tap twin OT, I fing that using an 8 ohm speaker with ther impedance selector in the 4 ohm position makes a HUGE difference. The sound becomes honkier, more compressed, and that allows turning up the presence control to past 2 o'clock and dialing in a very cool sound.

Interstingly, the above settings seem to work out with humbuckers and a Strat, and in the case of the Strat, it works in all 5 pickup pocitions. Very cool. One thing I did get rid of was a 20pF brightness cap I had on the OD Master pot, and I do not have a 47pF cap bypassing the pre OD 470K resistor.

That's pretty much it.

Cheers,

Gil

[JamesO]

Thanks for sharing your findings, Gil. I'm excited about finishing my Bluesmaster up quickly here. I've had to take a few weekends off from it.

How do you measure the trimmer's ohmage to ground? Scott gave me some numbers to work from, and I had planned on learning how to do that when the time came.

[ayan]

Thanks for sharing your findings, Gil. I'm excited about finishing my Bluesmaster up quickly here. I've had to take a few weekends off from it.

How do you measure the trimmer's ohmage to ground? Scott gave me some numbers to work from, and I had planned on learning how to do that when the time came.

Well, it depends on your meter... I can measurer everything in circuit. Other folks have to disconnect the HRM tone stack from ground to be able to measure. So, I measure from Mid HRM to ground, and then from Bass HRM to ground to get the values I quoted. Then, I donnect my meter between the wiper and ground lug of the treble pot and measure that.

I have been A/Bing my 100K amps and my BM, and while with the current settings the BM gets friendlier to play, the 100K non HRMs are a lot more old school, Boogie style if you will.

Gil

[Normster]

I haven't had a chance to get back into my BM yet, but it'll be interesting to try those settings. You guys made a believer out of me with the 4 Ohm setting, but I still think the amp sounds lifeless at low volumes. A Dumblelator with a bit of delay in the loop does wonders for it though.

[ayan]

I haven't had a chance to get back into my BM yet, but it'll be interesting to try those settings. You guys made a believer out of me with the 4 Ohm setting, but I still think the amp sounds lifeless at low volumes. A Dumblelator with a bit of delay in the loop does wonders for it though.

Regarding the Dumbleator + delay, does anyone NOT use that with these amps?

Also, CORRECTION on my initila post: I DO HAVE THE 47pF cap across the 470K resistor in front of the OD. [ I think all of us know -- it is a fact -- that when there is more treble up front which is bled to ground down stream, as opposed to vice versa, the tone is much juicier.]

Gil

[butwhatif]

Likewise with a non hrm, using a smaller snub on od1 and a bigger one on od2 makes for more personality in the od sound, especially w/ buckers. I've found it has more of the pickup's own tone in the sound. Then roll off the hi's at the master to taste- fwiw

[ayan]

Likewise with a non hrm, using a smaller snub on od1 and a bigger one on od2 makes for more personality in the od sound, especially w/ buckers. I've found it has more of the pickup's own tone in the sound. Then roll off the hi's at the master to taste- fwiw

Hi guys,

Thought I'd post a follow up since I had a chance to take the amp to work. First of, I chatted with Jelle about this and upped the treble bleed (from the lead master volume) cap to 220pF after realizing that my amp was not as smooth as the non HRMs with the previous, smaller cap. Anyway, I played the amp with a Strat, with band and at volume, and can make the following observations:

1. I may take the treble bleed up to 270pF, as the amp is still brighter than I would like it to be, especially in (mega) boost mode. I definitely prefer to keep the HRM treble up and deal with the brightness some other way, as opposed to turning down the treble control from the HRM, which kills the tone.

2. I like (with the EVM) to use the amp in 4 ohm mode, i.e., I mismatch the speaker impedance, and I like the sound of the presence control between 2 and 3 o'clock. I realize that will make the amp brighter, but it also adds something really cool in the midrange that sounds very good. I can see why TR (in their Type II) would have the equivalent of the presence hard wired full up and added a post PI treble cut, definitely the right direction as far as I'm concerned.

3. There is little doubt in my mind that the BM/boost is really "the" FR tone. Even with a Strat, the sound is going in that direction...

4. The tone is very cool indeed, but I am far from becoming a convert (from the 100K non HRMs). The sound is somewhat uneven in contrast with the other amps, and the midrange scoop introduced by the HRM makes the amp harder to sustain notes on command. This amp just doesn't get the "clean and infinite sustain" thing like the non HRM.

5. I also find that the best tones are with the Lead Master control turned way up. Anything before 1 o'clock and the amp is kind of lifeless, and by the time I hit 2 o'clock, it sounds tremendous.

6. Not cosmetically comfortable with the fact that the amp doesn't sound great with everything at 12 o'clock, like my other amps. The clean + boost has a lot of signal level on tap, such that while I have the Lead Master at 1 o'clock, I have to have the clean master no higher than 10-11 o'clock, otherwise clean + PAB will be louder than OD.

7. The PAB mode does introduce additional brightness (well, it increases everything, but overly emphasizes the brightness IMHO). Still toying withe the idea of using a small cap hardwired between the ground lug of the middle control and ground. I had played with less than 390pF before and liked the results, I will probably revisit that.

Anyway, that's all I have to pass on at the moment.

Cheers,

Gil

[Funkalicousgroove]

What kind of shielded cable did you use?

[ayan]

What kind of shielded cable did you use?

Same as in the last couple of amps I built, it's this Navy coax I got from Apex a couple of years ago. I think I measured on the order of 50pF per foot, or something like that? Funny you should ask, because I've often stopped to think that is the only thing I guess at least *I* have never checked in a real Dumble -- i.e., measuring the capacitance of the coax he uses. It doesn't take much to begin to make a big difference, especially in the case of the HRM amps. My non HRM amps never develop that icepick in the ear character in the first place, so they can be bright or not, but it's never an undesirable effect to me.

Gil

[Funkalicousgroove]

Nevermind, I already know the answer

I find these to be pretty great sounding with the 12L in the ported style cab, But I agree that the open back style with a 12L sounds a bit gnarly.

IMHO, the best speakers with the BM are the 2x12 with G1265's and the ported 1x12 with an EVM 12S.

that being said, the BM could NEVER be as smooth as a classic or a skyline with standard OD, but they have their own thing going on which as an island is VERY cool IMHO.

[ayan]

Nevermind, I already know the answer

I find these to be pretty great sounding with the 12L in the ported style cab, But I agree that the open back style with a 12L sounds a bit gnarly.

IMHO, the best speakers with the BM are the 2x12 with G1265's and the ported 1x12 with an EVM 12S.

that being said, the BM could NEVER be as smooth as a classic or a skyline with standard OD, but they have their own thing going on which as an island is VERY cool IMHO.

The difference between the 65s and the EVM 12L is night and day with the BM. One time a friend of mine, who has a TR 2x12 loaded with Celestion 65s, and I were tweaking the HRM in the BM. When we got it to sound "decent" with the EVM 12L, through the TR 2x12 it sounded completely muffled, like the tone control on the guitar was turned halfway down. Amazingly, however, a non HRM amp seemed to get along with both cabs pretty well.

Gil

[ayan]

Duplicate post

[Fischerman]

Thought I'd post a follow up since I had a chance to take the amp to work. First of, I chatted with Jelle about this and upped the treble bleed (from the lead master volume) cap to 220pF after realizing that my amp was not as smooth as the non HRMs with the previous, smaller cap. Anyway, I played the amp with a Strat, with band and at volume, and can make the following observations:

1. I may take the treble bleed up to 270pF, as the amp is still brighter than I would like it to be, especially in (mega) boost mode. I definitely prefer to keep the HRM treble up and deal with the brightness some other way, as opposed to turning down the treble control from the HRM, which kills the tone.

IMLE, a treble bleed off of the HRM Treble wiper (i.e. or from the Lead Master 'hot' lug) affects the HRM Treble control...however I've used larger caps with a series resistance so I'm not sure how applicable this is. It almost makes it sound like the HRM Treble control boosts mids as it is turned down...which it sort of is because a lot of the frequencies that the HRM Treble control passes are getting shunted to ground. It also seems to render the HRM Treble control more towards a 'harsh-muffled' control and it's even more difficult to dial it in (i.e. the tone quickly goes from harsh to muffled and finding the sweet spot is difficult).

I don't have a better alternative and still use a treble bleed though. I noticed that the Mesa Dual Rectifier uses a .0033uF cap in series with a 22K resistor plus a series 25K pot for the Red (lead) Channel...it is labeled 'Presence' and is simply a quasi-presence control for the Red channel. You'd think just putting it in the circuit would castrate the amp...but I'm not that familiar with those amps (other than recordings...some of which sound good). Then again they use a big 680pF treble cap in the Red tone stack...so maybe that helps.

[ayan]

IMLE, a treble bleed off of the HRM Treble wiper (i.e. or from the Lead Master 'hot' lug) affects the HRM Treble control...

Well, there is a 100K isolation resistor between the wiper of the treble and the input of the Lead Master volume, so it's not quite the same to do one VS the other.

Gil

[Normster]

I know we've talked about this before, Gil, but I like using a hi-cut control (ala 2rock) that switches in with PAB. A .005uF with a 250k trimmer seems to have the right range to it. I also hang a 470k resistor from the mid pot to ground so it's still brassy, but not over the top. I still haven't tried the 270pF to ground on the mid pot.