Complete Bluesmaster Layout

[mdroberts1243]

Hi Tony,
The current layout shows the mid pot as 50k Log... I think Scott had said Linear for this one.
I found that the mid-pot can swamp out the rest of the tone stack when turned up too much so linear helps in that position. BTW, in my personal build I have a 15k pot there... tends to give a decent mid level just below 12pm on the dial.

[mdroberts1243]

Hi Tony,
The current layout shows the mid pot as 50k Log... I think Scott had said Linear for this one.
I found that the mid-pot can swamp out the rest of the tone stack when turned up too much so linear helps in that position. BTW, in my personal build I have a 15k pot there... tends to give a decent mid level just below 12pm on the dial.

Oh, and the first two 47uF PS filter caps need to have the 350V rating (layout shows 250V like the others).

[talbany]

Mark
Thanks revision 4 up..

Tony

[jaysg]

I can also supply faceplate files for BNP Lasers.

Please sir!

re: above schematic. I don't claim to understand mdroberts' file naming convention, however, my guess is that one is version 7. I have one that seems to be version 12. I think he stopped updating the title block. I have more than one that indicates Dec 20, 2007 and 0.99

[UltraHookedOnPhonix]

Some more suggestions on grounding:

The bias tail resistor can be grounded to a ground lug just in front of the bias pot. Both 47uF, 160V bias supply caps should ground here as well and not with the PT.

Main filter caps should ground at the lug labeled, “GND 4”.

The screen filters (bottom right eyelet on PS board) should ground where the 150R virtual ground resistors ground.

[mbeldyga]

I found some errors in front page layout:
- orange connection between Volume and Treble pot should be connected to Treble center lug
- gray connection from R/J switch should be connected to most left lug on treble pot, not center

[talbany]

Thanks guy's Updated..

Voltages on the layout wold be a good thing..
Looking at the drop string I would imagine them being in the 180 range V1..Anyone?
Tony

[markusw]

Markus, The reason for the two 6k8 5 watt resistors in parallel no such value 3k4 in 5 watts.
I have never used a TF130 magic parts power transformer might have a high B+
I would be interested in a voltage chart.

Thank you, Steve.

Steve/ Markus

The real deal has the 2 parallel WW just like the layout.. BUT I cannot make out the values on them so this is a guess and I took them from the schematic that was posted a while back says 3K.. To let everyone know!!

Thanks

Tony

Thanks a lot for your informations!
So I guess using a 3W 3k or 3k4 should be fine too?

Regards,

Markus

[67plexi]

Makus, the photo I have shows 2 each 10 watt 6k resistors in parallel 3k value @ 20 watts overkill I think for the filter board. Also shows 220k resistors on the 220uf caps, not the 270k. The PPS is new to me I will find out. I'm starting with 3k @ 5 watts and 270k. the only reason I think HAD used such large resistors would be heat related issues. Only one way to find out build it.

Steve.

[Bob Simpson]

I didn't see it mentioned yet, but the ceramic cap on the mid boost switch on the front panel is labeled 391k in the layout, and 390pf on the schematic.

Thanks for all the time and effort.

Bob Simpson

[markusw]

Makus, the photo I have shows 2 each 10 watt 6k resistors in parallel 3k value @ 20 watts overkill I think for the filter board. Also shows 220k resistors on the 220uf caps, not the 270k. The PPS is new to me I will find out. I'm starting with 3k @ 5 watts and 270k. the only reason I think HAD used such large resistors would be heat related issues. Only one way to find out build it.

Steve.

Hi Steve,

I also think that 20W is way overkill.
If I didn't miss anything crucial I can't imagine that the Preamp+PI in a BM will draw much more current than e.g. in #124 which its seems was built with a 2W 2k2 at the same position.
Maybe HAD just had two 10W 6k or 6K8 resistors laying on his bench and therefore used them?

Regards,

Markus

[stevlech]

I didn't see it mentioned yet, but the ceramic cap on the mid boost switch on the front panel is labeled 391k in the layout, and 390pf on the schematic.

I may be wrong, but I think 391k is cap code for 390pf

[talbany]

Bob

The cap is labeled as what was in the amp

There is a three digit code printed on a ceramic capacitor specifying its value. The first two digits are the two significant figures and the third digit is a base 10 multiplier. The value is given in picofarads (pF). A letter suffix indicates the tolerance[1]:
C ± 0.25 pF M ±20%
D ± 0.5 pF P +100 −0%
J ± 5% Y −20 +50%
K ±10% Z −20 + 80%

Hope this helps..

Tony

[UltraHookedOnPhonix]

Makus, the photo I have shows 2 each 10 watt 6k resistors in parallel 3k value @ 20 watts overkill I think for the filter board. Also shows 220k resistors on the 220uf caps, not the 270k. The PPS is new to me I will find out. I'm starting with 3k @ 5 watts and 270k. the only reason I think HAD used such large resistors would be heat related issues. Only one way to find out build it.

Steve.

Hi Steve,

I also think that 20W is way overkill.
If I didn't miss anything crucial I can't imagine that the Preamp+PI in a BM will draw much more current than e.g. in #124 which its seems was built with a 2W 2k2 at the same position.
Maybe HAD just had two 10W 6k or 6K8 resistors laying on his bench and therefore used them?

Regards,

Markus

Markus,

All HRM's I've seen pics of (except one) use either one 10W or two paralleled 10W PI dropping resistors.

For anyone interested, use Ohmite 20 series.

I used two //6K, 10W for my build (pictured in this layout).

[markusw]

Markus,

All HRM's I've seen pics of (except one) use either one 10W or two paralleled 10W PI dropping resistors.

For anyone interested, use Ohmite 20 series.

I used two //6K, 10W for my build (pictured in this layout).

Thanks a lot for sharing your observations!
Any idea why HAD used 10W or even //10W resistors for HRMs/BMs while he used 2-3W resistors on some non-HRMs ?

Peace,

Markus