100w Bluesmaster HRM new build

[erwin_ve]

Erwin

here you are.

http://www.valvewizard.co.uk/gridstopper.html


M

Ahh it's Merlin Blencowe's page. He speaks from a very general viewpoint in that article without mentioning tube specs, better safe thank sorry in mind. 6L6GC with 440v on the plates can safely have 470 Ohm for the screen grid.

[norburybrook]

ooohh 3 relays...very little space...the FET board doesn't have room for stand offs so it wont fit where the chassis is drilled in the ANation chassis...hmm I'm going to have to get the drill out again and make more holes.....Interesting using a new chassis brings up annoying quirks in the build/Hardware mounting methods...other option is to try find some longer M3 countersunk screws...that make take a day or so however. So plan 'A' of re drilling new mounts will mean I can move on with this.


M

[Aaron]

I'll be back doing some more tomorrow. Met up with Aaron (sleepwalker amps) today and had a look round the guitar stores in London.


Great to actually meet a fellow TAG member I the flesh...especially as he's from the other wide of the world.

M

Great to finally meet a fellow TAG member! I’m nearly over my jet lag.
Going back to Hanks to try one of the Zonk Machines today.

Thanks,
Aaron

[norburybrook]

right hten.

Wiring done....Man that was fiddly, adding that FEt relay and the extra pot/ switch on the front really does make for some tight wiring and a lot more cable runs to and from things. I've used shielded multicore for all my runs from the FET /relays. The relay board had all the connections around the edge so it made jumpering and adding resistors a challenge. I would use a different board next time.

I've also cut my OT primaries so lets hope I've got them the right way round as I've also wire the leads form the PI under the board so they'll be a pig to swap too.

DSC_1830-01.jpeg

DSC_1831-01.jpeg

OK, time to get the light bulb limiter and apply some electricity!!


M

[pompeiisneaks]

Looking great!

I've learned my lesson on cutting OT leads, I cut them to size once and had it wrong and had to splice one, sucked. I always leave extra now, and go back and clean up after first power on.

~Phil

[norburybrook]

OK, it fired up ,no smoke,sparks,flames….

1st thing: Can't for the love of god get the power LED to work. I've swapped the LED, checked the diode, CLR and swapped the wires round, nothing!!! the wire from the CLR should go to the anode of the LED? the long leg, yes?



2: the FET works but in reverse, I can fix that on the switch

3: Neither of the PAB or OD relays work. I have 12v DC coming I to each and flicking the rear switch the voltage across the Diode goes from 0-12v.
What can I test to see if they're switching internally? it seems strange they both don't work.

I have no footswitch at the moment.

I'm on permanent OD at the moment and can't switch out of it, if the tone controls work I presume I'm not in PAB


Voltages at the moment:

v1: 215

v2: 210


V3:310



Power valves running around 480vDC I have the bias set to about 40, it's near the end of the range so which way do i need to go to put the range in the middle of the bias pot range? I'm on standard 3K3-10k pot 27k to ground.

TIA

Marcus


p.s. OT primaries were good...50% chance went my way this time.

[Guy77]

Hi Marcus, in regards to extending the range of your bias pot, I believe using a smaller resistor to ground will increase your range. You mentioned you were using 27K , you could try something like 20K and see how that works.If it makes it worse use one larger than 27k. Gorgeous looking build!

I am on vacation in a remote cottage in northern ontario and saw a nice sunset last night. I need to get out doors but ampgarage is too addictive!

Cheers

Guy

[pompeiisneaks]

To test if a relay is working is pretty simple, set your multimeter to continuity mode, and probe the middle and either end, in one way you'll get continuity, the other will be open, then hit the footswitch and see if that swaps.
That proves the relay's 'switching' is working. If it is, then the issue is elsewhere, if not, the relay coil may be getting charged backwards, I got this wrong on mine I had the + and - reversed and once I sorted that out, it worked.

~Phil

[erwin_ve]

Power valves running around 480vDC I have the bias set to about 40, it's near the end of the range so which way do i need to go to put the range in the middle of the bias pot range? I'm on standard 3K3-10k pot 27k to ground.

We need to know which end: in case of not getting a lower bias than 40mA you should up the 27k resistor.
If it's on the other end: vice versa.

[norburybrook]

it's on the low end so I need to up it. It's OK as it is in the fact I can get to 37mv which is 60% of the valves at 480V, it's just it would be better to have a bit more range.



The pilot LED and the relays are the strange issues.



M

[norburybrook]

To test if a relay is working is pretty simple, set your multimeter to continuity mode, and probe the middle and either end, in one way you'll get continuity, the other will be open, then hit the footswitch and see if that swaps.
That proves the relay's 'switching' is working. If it is, then the issue is elsewhere, if not, the relay coil may be getting charged backwards, I got this wrong on mine I had the + and - reversed and once I sorted that out, it worked.

~Phil

Phil,

Doing this I get no change throwing the switches on the back of the amp. I have taylors (AN) boards and Omron relays like I always use and have the diode in the orientation of the board layout, which is the same as Talbany's layout too. The main difference is the way the relay pins are connected to the eyelets which is different from the layout, I have taken that in mid though.

IMG_20180613_213828.jpg

looking at that picture are the diodes the correct way round? actually thinking about it nothing is happening when I flick the switches so would that make any difference? they would be working opposite I imagine , at the moment nothing is happening when I switch from pedal to manual on the rear switches. I have continuity from the anodes of the diodes with the rear switches that change from the middle to top or bottom so the switches are fine.

As I said there's 12v going to each relay and flicking the rear switches changes from 12 to 0v on across the diode. It just seems like the diodes aren't switching internally at all???????


I'm stumped....bloody relays, the bane of my life!!

[martin manning]

Marcus, do you have a diagram of the relay board traces?

[norburybrook]

as far as I remember when I looked at them closely they went top bottom top bottom top bottom.

relays 100w BM.jpg

hence me having to alter the wiring slightly form tony's layout.

edit: here's underneath.

DSC_1832.JPG

m

[martin manning]

Ok, same as in my DIY eyelet boards document. All of the connections are listed there. Boost is different, though.

[norburybrook]

Ok, same as in my DIY eyelet boards document. All of the connections are listed there.

as you can( or cannot) see, everything is connected exactly as per the layout. I 've used these boards quite a few times and never had this issue, I've had thing working backwards and LED's on and off in the wrong settings but never had both PAB and OD completely dead.

edit: looking at your boards it says Ratio/Master, is that for the #102 I'm doing a bluesmaster which has a separate master for the OD, I've followed tony's layout.




doing Phils continuity test and flipping the switches does nothing.


has this anything to do with not having a footswitch? I can't see how....I don't have any other 12v relays to check with. The FET relay which is a different make works fine.

could it be a current thing or would none of them work? I've got the 12v from the 23-0-23 tap into a 12v regulator. Not sure what the current rating is on that tap.

M