I'm stuck with my HRM build being too spoingy or rubbery sounding. The Clean master and ODmaster are really loud eaven at 1/2. I mean eaven not at 1 ?! I was adviced to check the grounds and I did that again but cannot find the problem.
I have studied the layout my build is based on: [img1255]http://bad-domain/97HRM/97_ODS_HRM_Loop.JPG[/img]
If I'm right the 22m resistors are not connected the same way on the two...
I was wondering if anyone more experienced could take a look for these two layout and schem to check if the switch area is not correct on the layout.
I've been struggling with this HRM build for all summer, tried to figure out if the layout is correct. I bought new semihollowbody + new pu's + celestion heritage 12-65 to improve the sound. But now I realise the problem is on my build and not on the other parts.
I surely will continue to try to figure the problem but could use some guidance
dogears wrote:First off Mat, the Dumbleator pots are audio taper. If you set the loop using linears on noon, you will get tons of gain!!!!
Where is the HRM stack ground??
I'll keep looking.....
I'm not sure of the dlator pots tapers. I'll take them of and check (cannot tell from looking at the back of the pots). The HRM stack ground is wired like this (also the corrections in light green I made earlier):
I'd bypass the D-Lator to see if that's causing your issue. You only have to move one wire, the output of the relay. Move it from the input of the D-Lator to the PI. If you still have the volume sensitivity issue at least you'll know it's not the D-Lator causing it.
Also, what are your voltages on V1 and V2? Measure pins 1-3 and 6-8.
From what I see the 22M's are connected the same as the ODS101 schem. These shouldn't change the sound at all anyway, they're only there to remove the click when you switch the PAB.
I'd bypass the D-Lator to see if that's causing your issue. You only have to move one wire, the output of the relay. Move it from the input of the D-Lator to the PI. If you still have the volume sensitivity issue at least you'll know it's not the D-Lator causing it.
The sound is eaven worse with the d-lator disconnected. More muddy and ..'jumpy'..
Also, what are your voltages on V1 and V2? Measure pins 1-3 and 6-8
193.8 1.84 197 1.77
199.2 1.86 211 1.83
From what I see the 22M's are connected the same as the ODS101 schem. These shouldn't change the sound at all anyway, they're only there to remove the click when you switch the PAB.
Ok, thanks for clearing that.
Btw. I wired the presence as in 101-schem and to my ears it is better that way. Only the basic problem still remains.
Work proxy is blocking them. I'll look from home. PM me all the values please. Double check the resistors. I suspect that one of the PI section resistors is either mislabled or the wrong value inserted in error.... Either that or your PI tube is bad.
mat wrote:
Here is your problem..... Pin 6 of the PI. Should be in the 250's......
Please take a picture of that area where I can see the color bands.
Funkalicousgroove wrote:Do your front pannel tone controls work? Mainly the treble is what I'm concerned about-
Yes they work ok when the PAB is not engaged. What do You see in there that made You ask ? I just went and checked the wiring of the treble pot and it is just like on the picture.
Funkalicousgroove wrote:Oh, I had an amp with similar symptoms a while back, turns out that I managed to wire around the slope resistor!! Must be the solder fumes LOL!
dogears wrote:Here is your problem..... Pin 6 of the PI. Should be in the 250's......
Please take a picture of that area where I can see the color bands.
mat wrote:
Other voltages:
PI (marshall style)
1-263
2-30
6-207
7-30
8-46.8
Power tubes
3-484
4-472
5- -41.8
8-0.034
3-483
4-471
5- -42.6
8-0.028
Bias 32 32 (seperate measuring points).
I don't know why I got the 207V reading on PI's second plate. I noticed a loose snubber in there. I did put in a fresh 30p one and now the plates are 265 and 237. Does that seem right ?
The sound is actually quite nice when playing very, very softly but as soon as digging in a little bit more the sound gets really harsh
1255]http://bad-domain/97HRM/97_ODS_HRM_Loop.JPG[/img]
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