Get fat, no buzz from HRM amp. Read if you are deperate...

[Tonegeek]

After reading about how many people are less than satisfied with their HRM amps (in OD mode) and hearing about how hard Strats are to get sounding good on these amps, I decided to try and kill two birds with one stone. Please don't do this until your have exhausted the help from those forumites (like Scott 'dogears') who are getting excellent sounds from their HRM amps using known values. This message is for those of you that have really tried working with the known Dumble values but have finally given up in frustration and are ready to try something more radical. In a recent, excellent thread, Gil ('Ayan') talked about his experience with the HRM culminating in converting it to a non-HRM. It made me want to build a non-HRM! Here is another option, one that worked for me. My suggestion is for those of you who are experiencing a thin, buzzy OD sound. This should help Strat owners more than anyone.

Here's my setup and if yours is close, this may work for you. BTW- The fat tones of Robben Ford ('Politian') and Eric Johnson ('Cliffs of Dover') are what inspire me the most.

Mex Strat
2 X 12" G12H-30 speakers, open back cab.
Skyline eq.
Bluesmaster values everywhere else (v2 coupler = .01) BM PI
OD entrance is pretty normal 470k || 47p > 100k trim > ground. The trim wiper > 68k > OD1 grid
A low gain trimmer (25k) should work too but you might need more resistance between it and the 470K.

Many folks look to the OD entrance as the place where all the action is. For me it is the HRM that had the biggest effect on getting the sound I was after. The 500p, .02, .02 values just plain do not work at all for any of my guitars.

Heres the tweak (try modeling this next to the accepted values with the Duncan TSC (Marshall, not Fender tab) to see where I am going here):
replace the HRM treb cap with a 2n ceramic cap. I used 2x.001 ceramic caps
replace the HRM mid cap with a 3n3 cap. (I used a 2n + 1n)
wire the mid trimmer like a Marshall (mid cap to the wiper which is NOT tied to input)
leave the bass cap at 20n for now
Set your OD input trimmer pretty low to start (mine is 7.5K from wiper to ground)
Input volume is about 60%
Drive is about 55%
Try playing With just OD on (no PAB, or mid boost). Set the HRM bass trim first for the desired bass (mine is about 30% up). Put the mid and treb trims half way up.

With just OD on (no PAB, or mid boost) I have been able to get the OD to sound about like the clean channel (but slightly fuller with some crunch) by twiddling with the HRM trimmers (yes they still work, but very subtle now as you can imagine). With OD and Mid boost my sound is very fat and almost no buzz. I think the slight artifacts I still hear are from the BM PI, which I am considering replacing with the 24k PI) but I am still very happy with this setup.

The mid cap is where you can really do some tweaking. If the sound is too middy try raising the cap to 4n. If you want more mids go to 2n. A guitar with humbuckers may need a larger mid cap or go to 1n on the treble cap. Also the relationship between the OD input trim and the Drive control can affect the character. You can experiment here. I find I get feedback easier with the trim higher and drive lower, but more definition the other way around. The eq changes a bit too with this relationship. I am also experimenting with a 47n bass cap with some good results. Comments are welcome....
Happy holidays
whit

[dogears]

Whit,

Are you saying that you have the wrong OD network? You are missing a 120K there, between the 470K and trimmer. Total load should be around 690K then.

Unless you consciously decided to axe it. But, without it, you would certianly be prone to a thinner and buzzier sound.

[G-Dorian]

I've been reading the threads where people say they can't get a decent strat tone with HRM - or that they just don't like HRM.

I believe Robben Ford uses HRM. But he also uses a strat on Jing Chi 3D - and his tone is excellent. He also uses a tele with HRM, and again, excellent tone. In fact, his tele sounds like he's using humbuckers (Ford Brothers' "In Memory Of Michael Bloomfield" - song: "I've Got a Mind To Give Up Living").

So my question is, how is he getting such good tone from HRM while others are not?

Robben's HRM OD tone is very smooth - non-HRM territory. Is it possible to get the smooth tone of non-HRM and get the cleans of HRM? (Forgive me for my ignorance here.)

Greg

[G-Dorian]

I wanted to add that Robben's tone has thick mids and is darker than I've heard from other's HRM clips (e.g., "I've Got A Mind To Give Up Living" - very dark).

Maybe that's part of his secret?? I've read where some people have the mids and bass set low, while their treble is set pretty high. I don't know, just jibber-jabberin' . .


. . . (I know when Robben and Larry were in town a few months ago, Robben's amp tech put in JJ preamp tubes, which are darker. It all counts towards his tone . . )

[heisthl]

Whit,

Are you saying that you have the wrong OD network? You are missing a 120K there, between the 470K and trimmer. Total load should be around 690K then.

Unless you consciously decided to axe it. But, without it, you would certianly be prone to a thinner and buzzier sound.

My experience with the entrance load is the opposite - more resistance thinner, less resistance bassier. I'm tempted to start putting a 100k wired as a VR on future builds here to "tune to the iron" and find the spot that's the least buzzy with acceptable fullness.

[dogears]

Greg,

You have to look at the facts.

1) Dumble likes HRM. He converted or built many in the course of Evolution.

2) Artists such as Sonny Landreth, Robben Ford, Larry Carlton, and Santana, play HRM amps (fact) or in RFs case there is strong audio evidence he does.

3) Respected (LOL) builders such as Funk, CSanford, Myself, Alan Philips, Brownnote, and Bob I, love HRM and have gotten it to sound great. Joe Bonamassa, Dave Grissom, and Eric Johnson all love their Carol Ann amps which are based on Dumble HRM w/Bluesmaster circuits.

4) Although I love Gil, he is a neck pickup guy who loves silky smooth OD that doesn't have that harmonic growl. It is really no surprise he loves the tried and proven 80s circuit of which he is the master! Different strokes.... He also never tried his setup with the Celestion G1265 or Eminence RWB. To my ears the EVM is not so nice with them. Although Carol Ann uses them.

5) Without clips to demonstrate a baseline, opinions for me carry less weight. I'd like to hear to determine in my mind what is wrong with the tone.

6) Some guitars really don't sound so good.

7) HRM amps can be harder and less forgiving. Some players won't bond with it.

I could try and go on and on..... LOL

[dogears]

Totally disagree. If you don't have a resistor between the preemphasis network and the trimmer, you will have less bass. There will be more gain on the emphasized frequencies. In addition, the knee is higher since you change the load against the CL2 cap . You may feel there is more bass because there is actually less and it is more open and less hard. I was referring to having the bright cap network with nothing after.

Whit,

Are you saying that you have the wrong OD network? You are missing a 120K there, between the 470K and trimmer. Total load should be around 690K then.

Unless you consciously decided to axe it. But, without it, you would certianly be prone to a thinner and buzzier sound.

My experience with the entrance load is the opposite - more resistance thinner, less resistance bassier. I'm tempted to start putting a 100k wired as a VR on future builds here to "tune to the iron" and find the spot that's the least buzzy with acceptable fullness.

[Tonegeek]

Whit,

Are you saying that you have the wrong OD network? You are missing a 120K there, between the 470K and trimmer. Total load should be around 690K then.

Unless you consciously decided to axe it. But, without it, you would certianly be prone to a thinner and buzzier sound.

Agreed. I took the 100k out after I changed my HRM. Pre HRM change, I tried 100k and 200k with and without the 47p over the 470k but apparently something else was keeping it buzzy. Also tried 5uF on OD2 during that period but got mud as i did when I upped the OD1 coupler from .0022. I will try some of your other ideas soon though...

[tubedogsmith]

I wanted to add that Robben's tone has thick mids and is darker than I've heard from other's HRM clips (e.g., "I've Got A Mind To Give Up Living" - very dark).

Maybe that's part of his secret?? I've read where some people have the mids and bass set low, while their treble is set pretty high. I don't know, just jibber-jabberin' . .


. . . (I know when Robben and Larry were in town a few months ago, Robben's amp tech put in JJ preamp tubes, which are darker. It all counts towards his tone . . )

If you're talking about the song on the Bloomfield tribute album that was a superb reverb and Boss DS-1

[groovtubin]

I've been reading the threads where people say they can't get a decent strat tone with HRM - or that they just don't like HRM.

I believe Robben Ford uses HRM. But he also uses a strat on Jing Chi 3D - and his tone is excellent. He also uses a tele with HRM, and again, excellent tone. In fact, his tele sounds like he's using humbuckers (Ford Brothers' "In Memory Of Michael Bloomfield" - song: "I've Got a Mind To Give Up Living").

So my question is, how is he getting such good tone from HRM while others are not?

Robben's HRM OD tone is very smooth - non-HRM territory. Is it possible to get the smooth tone of non-HRM and get the cleans of HRM? (Forgive me for my ignorance here.)

Greg

http://www.myspace.com/omegaamps

HRM std PI values ( 820/24K/390) std low gain entrance, lile dark, i didn`t have time to dial ANYTHING in, the guy was in a hurry.
jim

[Fischerman]

I just put that stuff into the Marshall stack on Duncan's TSC and it's a ton more mids (as expected from the mid and treble cap values). It looks like the mid control and treble control basically do the same thing (although the Treble control has way more range)...does it sound like they do the same thing Tonegeek? It even looks like the mid control now controls the treble without affecting the mids much at all.

Interesting stuff Tonegeek. I'm still thinking that mine just doesn't overdrive worth a shit so I might try Gil's quickie conversion just to see if this amp can give me something to like about it (other than the clean). At this point...I hate the damn thing and kinda wish I hadn't gone to the trouble (come to think of it...same with my Trainwreck clone...hate it). Maybe I should stick to Marshall circuits...that's home.

[G-Dorian]

Scott -

I completely respect all the amp builders on this forum. But I think you misunderstood my post. I have read not just this one thread, but others where guys have voiced frustration with HRM amps.
I have also read where people have set their trimmers (other than that, as you know, I have no clue about internal values). But my point was about Robben's tone. It has thicker mids and is darker than what I've heard from HRM clips.

That's the only point I was making: that perhaps adjusting whatever needs to be adjusted in order to get their HRM amps to be a little smoother, less trebly, more mids, would allow them to get a smoother OD tone.
From experience, I have found that more treble can lead to more harshness/uglier OD tone. Robben's tone is darker and smooth.

Like I said, I meant absolutely no disrespect to anyone. I'm just goin' on what I read from some people and what I've heard. I was just offering a suggestion.

Greg,

You have to look at the facts.

1) Dumble likes HRM. He converted or built many in the course of Evolution.

2) Artists such as Sonny Landreth, Robben Ford, Larry Carlton, and Santana, play HRM amps (fact) or in RFs case there is strong audio evidence he does.

3) Respected (LOL) builders such as Funk, CSanford, Myself, Alan Philips, Brownnote, and Bob I, love HRM and have gotten it to sound great. Joe Bonamassa, Dave Grissom, and Eric Johnson all love their Carol Ann amps which are based on Dumble HRM w/Bluesmaster circuits.

4) Although I love Gil, he is a neck pickup guy who loves silky smooth OD that doesn't have that harmonic growl. It is really no surprise he loves the tried and proven 80s circuit of which he is the master! Different strokes.... He also never tried his setup with the Celestion G1265 or Eminence RWB. To my ears the EVM is not so nice with them. Although Carol Ann uses them.

5) Without clips to demonstrate a baseline, opinions for me carry less weight. I'd like to hear to determine in my mind what is wrong with the tone.

6) Some guitars really don't sound so good.

7) HRM amps can be harder and less forgiving. Some players won't bond with it.

I could try and go on and on..... LOL

[G-Dorian]

OK, but on Jing Chi I still hear thick mids and a darker tone.
I don't mean this as any sort of argument. I'm only saying that Robben's HRM tone is darker to my ears.

I wanted to add that Robben's tone has thick mids and is darker than I've heard from other's HRM clips (e.g., "I've Got A Mind To Give Up Living" - very dark).

Maybe that's part of his secret?? I've read where some people have the mids and bass set low, while their treble is set pretty high. I don't know, just jibber-jabberin' . .


. . . (I know when Robben and Larry were in town a few months ago, Robben's amp tech put in JJ preamp tubes, which are darker. It all counts towards his tone . . )

If you're talking about the song on the Bloomfield tribute album that was a superb reverb and Boss DS-1

[dogears]

Greg,

Watch the vids of Carlton and Ford. Robben is pretty bright live. We don't know how they are micing his cabs in the studio, and if effects ro EQ are applied in the mix.

Having said that, I do not find either HRM amp at my house to be bright. Bob I can corroborate that when he heard mine next to his.

I also do not know of Robben using a strat with Dumble on any OD solo tones. Live Jing Chi is the Crucible or the Tele.

[G-Dorian]

Scott -

I saw Robben and Larry live back in August. From where I was sitting (middle of the theater), Robben's OD tone was dark and got lost a little in the mix.

When I had my Glaswerks, the 90's voice was too bright , which was part of the reason I didn't like it.

On my site here, the song "New Creation" was done with my old Glaswerks in HRM mode. Bright.

www.myspace.com/gregmwmusic

True, we don't know how Robben's amp is recorded, but live it was still dark with thicker mids, to my ears - whereas, Larry's amp was very bright.

On the back of Jing Chi 3D there is a pic of Robben holding his strat during a session. ("Blues Alley" is a strat OD tone.)

This isn't an argument. The original poster of this thread said that he was having a hard time getting a good strat tone with his HRM. I offered a suggestion and an opinion.
If you want to think I'm wrong, that's fine. I have no problem with that.

Greg,

Watch the vids of Carlton and Ford. Robben is pretty bright live. We don't know how they are micing his cabs in the studio, and if effects ro EQ are applied in the mix.

Having said that, I do not find either HRM amp at my house to be bright. Bob I can corroborate that when he heard mine next to his.

I also do not know of Robben using a strat with Dumble on any OD solo tones. Live Jing Chi is the Crucible or the Tele.

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