seperate clean/OD masters

[mat]

How should I wire the seperate clean/OD masters. Any layout/schems showing that ?

I'm just finishing my HRM build and while the cleans are superb, the OD is way too harsh. On the other topic this was the cure for the harshness.

My build (2x6L6) is based on Normsters (now verified) layout [img1255]http://bad-domain/97HRM/97_ODS_HRM_Loop.JPG[/img]

[Normster]

That layout already has seperate clean/OD masters so you should be good to go. Have you adjusted the post-OD tone stack yet? It seems to be very touchy so maybe spend some time with it and see where it takes you.

[mat]

That layout already has seperate clean/OD masters so you should be good to go. Have you adjusted the post-OD tone stack yet? It seems to be very touchy so maybe spend some time with it and see where it takes you.

Oh.. Now I see, You were talking about 'Master bypass' and not 'separate masters' - my mistake.

Yes I have tweaked the trimmers but I have to tweak more I think. Comparing to my nonHRM build which has very sweet OD the HRM is really too harsh. I use the same speaker + cabinet when comparing the two. I'll record something to show the difference.

[dogears]

Mat,

Is your OD1 coupler a .002uf? If so, this is too small. It should be a .0022uf. That is 10% and trust me, it is very noticeable. The knee frequency moves quite a bit. You'll regain lows and low mids to balance those highs. There is no PS series in .0022uf. Just use something else.

Don't give up. The HRM, when properly built is very sweet with that straining tone that instantly reminds you of late era Robben. Not harsh at all. I prefer it to 80s voice.

Maybe lift the HRM stack and measure and post you settings. If your mids are 50% up or more it will be harsh. Did you fix the trimmer size yet?

[mat]

Hello dogears,

Is your OD1 coupler a .002uf? If so, this is too small. It should be a .0022uf. That is 10% and trust me, it is very noticeable. The knee frequency moves quite a bit. You'll regain lows and low mids to balance those highs. There is no PS series in .0022uf. Just use something else.

I'll open it up tomorrow and check the cap. Maybe I'll try to put smaller cap in parallel with the .002.

Btw. the trimmer that is connected to OD1 grid is a 22k one and not 25k. Might that be the problem ?

Don't give up. The HRM, when properly built is very sweet with that straining tone that instantly reminds you of late era Robben. Not harsh at all. I prefer it to 80s voice.

Thanks for the engouragement, I hope I get it fixed some day .Late era Robben is THE sound for me

Maybe lift the HRM stack and measure and post you settings. If your mids are 50% up or more it will be harsh. Did you fix the trimmer size yet?

I didn't fix the trimmer yet but maybe I'll have time tomorrow to do that. Meanwhile here is a sound sample of first the HRM amp and then the nonHRM with same mic-placement-cab-speaker(RW&B).

This sample does not give the whole picture of the case because I have on the HRM pair of 6L6's and on the non HRM there is JJ6V6's which are not as 'glassy' or 'singing' sounding as the 6L6's. 6V6's are nice but not what I'm after for now. The 6V6's does smooth the difference between the amps on the soundfile..

Couple pictures of the settings:
http://www.pichotel.com/pic/16028B31e/139908.jpg
http://www.pichotel.com/pic/16028B31e/139909.jpg
http://media.putfile.com/hrm97

All in all I could swear that the amp sounds better and better each day. The more it is used the better it sounds. Also I have on HRM cabinet a brand new RW&B that does sound very bad comparing it to the other RW&B that I've been using about one year.

Btw. I got the d-lator bug fixed (wiring error). The first (HRM) section of the soun clip has d-lator with some delay+reverb init. On the non HRM section there is the amps own reverb at abot 8-9.

[mlp-mx6]

All in all I could swear that the amp sounds better and better each day. The more it is used the better it sounds.

You are not the first person to recognize this. I count myself among that number also. I've heard various theories, but I really don't care why. My amp ABSOLUTELY sounds better after several hours of play.

Keep playin'!
Michael

[Tonegeek]

+1 on the .0022 making a diff. On Dogears recommendation, I changed mine. (Sozo makes a 400v .0022 cap). I also opened up the 250k drive pot (which only actually measured 220K) and scraped off some of the carbon on the outer edge to raise the resistance. The new RC combination lowers the corner Freq. (about 10% as Dogears mentioned) to beef things up a bit. Also +1 on Normster's suggestion to play with the HRM settings a lot. I am still messing with mine. At some point you will get "that magic feeling" when it is right. You probably already know this, but the OD sounds better with PAB on too.

The gain structure has an effect on the overall sound also, especially if you have outboard effects, D'lator, etc. I can fatten up or thin out my amp somewhat just by messing with the gain structure.

I must agree also that I experience my amp sounding better the more I play it. I have heard theories ranging from cap forming to transformer magnetics. Then again I think my amp (really every amp i ever owned) sounds different depending on the temperature and humidity too. One day it sounds intolerably thin and harsh and with no other change than some time going by, it sounds sweet and full. The good news is that the thin, buzzy days are about gone as I tweak and as the amp burns in. I think it has to do with increasing the range of the "sweet spot" so that if you do have outside factors like the weather to deal with, the amp can compensate.

[benoit]

Haha... mat, I clicked on your clip without thinking while I was already listening to a song by hifi handgrenades and it just happened to be in the same key and damn near would have worked on the record Completely OT but cool too...

[mat]

Haha... mat, I clicked on your clip without thinking while I was already listening to a song by hifi handgrenades and it just happened to be in the same key and damn near would have worked on the record Completely OT but cool too...

btw. did not had time to open the amp today Just little time to play it and it really sounds too hard if that makes any sense I'll open it tomorrow and measure all the voltages again and check the cap + HRM settings...

[dogears]

Hey Mat,

Try a 300ohm to 500ohm resistor in place of the choke.

Also, try EL34 tubes. HRM loves EL34

[mat]

Hey Mat,

Try a 300ohm to 500ohm resistor in place of the choke.

Also, try EL34 tubes. HRM loves EL34

Ok, I'll try the resistor. I have standby switch on my non HRM that chooses between choke or 500ohm. I usually prefer the choke.

I have EL34's on my trainwreck express copy, I'll rob them there when I have next band practises on sunday. Don't much like the express.. too harsh distortion for my taste (at least on my copy )

Will report back,

[philmanatee]

Hey Mat,

Try a 300ohm to 500ohm resistor in place of the choke.

Also, try EL34 tubes. HRM loves EL34

Ok, I'll try the resistor. I have standby switch on my non HRM that chooses between choke or 500ohm. I usually prefer the choke.

I have EL34's on my trainwreck express copy, I'll rob them there when I have next band practises on sunday. Don't much like the express.. too harsh distortion for my taste (at least on my copy )

Will report back,

I wouldn't give up on your express, they are very picky about what tubes sound good in them. Phil

[mat]

Measured and adjusted the hrm trimmers as follows:

Treble: added 30k in between the 500p (actually470p) and the 220k treble trimmer. It reads 142k between the 30k's cap side and the viper.

Bass (1M) reads 400k across the viper and the outern lug. Less that 12:00 o'clock.

Middle reads 9k4 across the viper and the outern lug. About one fourth/fifth on.

OD coupling cap was already 0.0022.

The 25k (actually22k) OD trimmer is about 90%

The V2a voltage seem to be quite low:

B1 474
B2 472
B3a 352 (d-lator)
B3b 287 (d-lator)
B4 451
B5 325
B6 319

V1 1=197,8 3=1,8 6=204 8=1,68
V2 1=197,5 3=1,8 6=215 8=1,66
V3 (d-lator) 1=286 3=18,8 6=224 8=1,87
V4 (PI) 1=279 3&8=44,6 6=250

The sound has lots of harmonics and stuff but it is still way too bright/harsh (I test always with boost on, mid boost off, bright off).

Tweaking the d-lator send and return smoothens the sound somewhat.

I tried other tubes to V2 without improvement.

I changed the choke to 500ohm and noticed slight softness on the pick attack.

The OD sections 'drive'-pot does add lots of volume to the sound, not so on my nonHRM ? I have to crank the OD ratio-pot to have balance between OD+boost and clean+boost.

soundclip where it is now. About halfway I stick a 4n7 715 with the sealed alligator clip on parallel with the .0022. It strenghtens low mid range but does not improve the harshness problem (this was just something I was curious to try..)

http://media.putfile.com/hrmblues

[Bob-I]

Measured and adjusted the hrm trimmers as follows:

Treble: ...500p (actually470p)

This can make quite a difference. I'd either get a 500pF or pur a 39pF across the 470pF to get closer to 500pF

The V2a voltage seem to be quite low:

V1 1=197,8 3=1,8 6=204 8=1,68
V2 1=197,5 3=1,8 6=215 8=1,66

That is odd. I'd double check the plate load and cathode resistors, as well as the bypass cap for correct value. Something's off here.

The sound has lots of harmonics and stuff but it is still way too bright/harsh (I test always with boost on, mid boost off, bright off).

I can't hear it in the clip, sounds great to me.

The OD sections 'drive'-pot does add lots of volume to the sound, not so on my nonHRM ?

That doesn't make much since. Both should change the volume quite a bit.

http://media.putfile.com/hrmblues

[mat]

Hi,

This can make quite a difference. I'd either get a 500pF or pur a 39pF across the 470pF to get closer to 500pF

Ok, it has now the 33pF also.

The V2a voltage seem to be quite low:

V1 1=197,8 3=1,8 6=204 8=1,68
V2 1=197,5 3=1,8 6=215 8=1,66

That is odd. I'd double check the plate load and cathode resistors, as well as the bypass cap for correct value. Something's off here.

Ok, I checked the plate load and cathode resistors (one 2k55 instead of the 2k7) and they seem to be ok. Also the 4.7uF and 1uF are as expected.

The sound has lots of harmonics and stuff but it is still way too bright/harsh (I test always with boost on, mid boost off, bright off).

I can't hear it in the clip, sounds great to me.

The amp in person is way too bright and shrill (is that an word?), not lively at all.

The OD sections 'drive'-pot does add lots of volume to the sound, not so on my nonHRM ?

That doesn't make much since. Both should change the volume quite a bit.

Ok, no wiring error there then (checked, did not found one).

I think I'll try to adjust the dropping string for V5 and V6 to get the V5 to behave

EDIT- changed the last two droping resistors and now the V1,V2 plates are 201,210 and 203,216 - just did not have change to play the thing on proper volumes

Thanks for the tips,