100w Bluesmaster HRM new build

[norburybrook]

OK,

so I've reversed the diodes and the wiring.

Now when I've got both switches on pedal I have the OD channel on and the PAB off, when I switch to manual I have clean and PAB on.

so 1 step forwards.....at least relays are working now.


So the OD/clean is working the wrong way round and the PAB is correct?


as I don't have a footswitch I've no idea which way round will be correct for the LED on off either.





M

[martin manning]

As I noted above, this thing has OD on when the relay is not energized. That’s how it’s drawn. LEDs are on when the relay is energized. Switch NO and NC connections in the OD relay to get LED on when OD is on.

[norburybrook]

As I noted above, this thing has OD on when the relay is not energized. That’s how it’s drawn. LEDs are on when the relay is energized. Switch NO and NC connections in the OD relay to get LED on when OD is on.

NO 1 and NC 1 ? so swap the OD volume wiper with the CL volume wiper on the relay board.

M

[martin manning]

See above in the post with the connection table...

[norburybrook]

actually martin, I've quickly made a footswitch and with it plugged in everything works as it should

IMG_20180614_145203.jpg

IMG_20180614_145238.jpg

So all good, thankyou.


I now realise i have some tweaking to do to the switch LED's as the first one is getting more current/voltage than the others in the chain. I think Charlie Wilson had a threads about this a while ago i'll take a browse through that.

I'd forgotten what a LOUD amp this is With the OD on you have to be very careful with the FET boost or it goes into self oscillation!!!

M

[sluckey]

I now realise i have some tweaking to do to the switch LED's as the first one is getting more current/voltage than the others in the chain.

Don't think too hard about this. If you want a dimmer LED just use a larger resistor.

[norburybrook]

I now realise i have some tweaking to do to the switch LED's as the first one is getting more current/voltage than the others in the chain.

Don't think too hard about this. If you want a dimmer LED just use a larger resistor.

that's my kind of reply

thanks Steve.

M

[norburybrook]

right, here's where I'm at.

Voltages

V 1 plates 218 and 210
V2: 217 and 210
V3: 286 and 308

6L6's ~485VDC

I've got it biased at 44mV at the moment which is probably a bit hot so I 'll mess with the resistor to get some more wiggle room to get it down to ~37mV

I put a 2k2 on the green LED at then end but it hasn't made much difference you can still see it from space.


I don't think I need to drop the V1 and 2 voltages, what do you think?



I've got blue suede for the cab hence the coloured knobs, thought I'd have some fun with this one.

IMG_20180614_153209-01.jpeg

IMG_20180614_153152-01.jpeg

IMG_20180614_145238.jpg

time to start thinking about a head cabinet now then....


M

[talbany]

Marcus
What are you using for a treble cap on the HRM board
BTW.Voltages look OK depending on the tube you might get a 10V swing either way..Roll tubes until you are happy!..Try to set the PI roughly 6V higher on the NFB side and tweak from there.

Tony

[norburybrook]

Marcus
What are you using for a treble cap on the HRM board

Tony

Its a 500pf polypropylene. It was in my cap box so I used it

It's a very smooth sounding amp so far. I haven't tweaked the HRM yet, got everything on mid way. Used 25k and 2x250k pots.

I can actually use the bright switch for the first time on this amp, not sure why. Possibly the master bright and bright caps are not those little cheap ceramic disks? who knows, very smooth...……..AND VERY LOUD

M

[pompeiisneaks]

Excellent! Glad you got the relays sorted, was also the biggest trouble for me, but I figured out how to get it going with Charlie Wilson's help

~Phil

[sluckey]

I put a 2k2 on the green LED at then end but it hasn't made much difference you can still see it from space.

Bigger, bigger, bigger. Or try this...

[norburybrook]

Excellent! Glad you got the relays sorted, was also the biggest trouble for me, but I figured out how to get it going with Charlie Wilson's help

~Phil

Phil,

I'd no idea Omron relays came in polarised and non-polarised versions of the same relay. it was just unfortunate that i got the wrong ones this time. If i'd have got the right ones then I'd have had the perfect build for once!!!


removing leads and components from the relay boards when they're in situ is a difficult job and you end up making them look a mess.


M

[talbany]

Cool!.. IIRC the OD entrance pot and HRM stack was set with the clean stack out of circuit in the originals (or in PAB mode).in order to shift the primary stack later in the stages (ala 2204 Marshall)..You of course can tweak it however you use it..The main stack in the BM is a different animal than a Skyliner so you will notice a difference in how the stack operates (bright switches mid boost etc) along with the Presence control! again ala Marshall..IMO these amps really shine with 34's but this is purely a matter of taste..The clean channel in the BM is by far my fave of all the ODS cleans 2nd gen a close 2nd!! Glad you got it working
BTW.LOUD=Healthy
Good Luck!

Tony

[norburybrook]

Marcus
What are you using for a treble cap on the HRM board
BTW.Voltages look OK depending on the tube you might get a 10V swing either way..Roll tubes until you are happy!..Try to set the PI roughly 6V higher on the NFB side and tweak from there.

Tony

just swapped the 'balanced' PI JJ valve for a Sovtek 12 AX7 LPS, that's now made adjustment perfect and I've got 6v higher on the NFB side. the JJ was way off...'balanced' I think not!


I've got an EHX in V1 and one of those China 6N4J / ECC83 / 12AX7 High Grade NOS in V2 and a set of 4 x Tube town 6L6GC https://www.tube-town.net/ttstore/Tubes ... :3182.html I thought I'd ordered JJ's but obviously not. they seem fine so far.....very hot!

M