First pic of 36 watt board ?

stevesuk · Post by **stevesuk** » Mon 02/16/04 2:55 pm

Attached is a pic of my 36 watt on a standard RS 27 X 7 hole board prototype populated board. The 125 ohm 5watts are under the board and the 8.2 Ks will be off it. Thanks Richie, great idea. This is the 5th attempt to fit everything on the board, just not possible.

I will post some high res pics on my gallery steveUK when it comes back on.

Steve UK

Post by **Graydon** » Tue 02/17/04 12:52 am

Wow,

Very nice! I am green with envy!

Post by **zaphod_phil** » Tue 02/17/04 7:51 am

This 36W thing is reminding me of the "space race" when Russia and the USA were competing for who would put a man in space and then on the moon, first. So at the moment stevesuk is in front!

stevesuk · Post by **stevesuk** » Tue 02/17/04 8:03 am

Maybe, but I'll need Richie to tell me why it's not working !!

Steve UK

Post by **Plexi** » Tue 02/17/04 8:58 am

HAHAHA.. Steve, we've seen yor other amps, you'll do fine.The board looks great.. I thought you were shy-ing away from the OD caps..You usually use all those great RS parts you get over there..

The moon has already been done,Mars is nice..since combined with my last name is Mars-Hall...
But with anything,when something is built,usually after the first one, you see ways of doing things different, or better way,learn from a mistake etc..
or things get refined as it goes. Hopefully we will be ok,Since its not much different at all from a stock 18. And as you can see, some of us will be building a bit different,like a head or combo, Stock, or TMB..or different parts used.
The one thing is ,we are not really in a race,we are just anxious,to get one together. And we are helping each other,if they need it.
Another good thing for me is, i have a stock 18 here, and an AC 30..so when i get done, i can do side by side testing,and see how it compares.
Richie

Post by **Plexi** » Tue 02/17/04 9:05 am

"""So at the moment stevesuk is in front! """

Don't forget, Graydon is in there too, hes in his secret lab,sneaky devil,he pops up stuff like red mini stacks,offsets and lots of stuff you never know of..lol:) And hes been working on a 36 too.. As i'm sure some others like Dan B. are doing these .

Richie

Post by **Graydon** » Tue 02/17/04 9:28 am

Man! You guys are the worst! I can't believe you would stoop to these depths! I was enjoying some R&R with my family, just leisurely finishing off the last few details of a really hot 100W before I ship it to it's new owner. Now you put this kind of pressure on me! I have too many amps to build. I can't take time away from that to embark on a frivolous endeavour such as the 36W. I hereby request that we close the 36W forum temporarily until I can get caught up.

Post by **Plexi** » Tue 02/17/04 9:39 am

Someone blow out the fuse to the spaceship on the launching pad..LOL
Too late, can't turn back now.. Doesn't matter,who is first to get theres going..it has to start somewhere.. I think the first radios were something like that too..
Richie

Wannatone · Post by **Wannatone** » Tue 02/17/04 9:43 am

Steve,

your board looks exceptionally nice!

IÂ´m sure it will work like it looks, maybe just replace the ODÂ´s...

Btw, I wonder where you get the perforated board? Could need some..

Adrian

stevesuk · Post by **stevesuk** » Tue 02/17/04 10:31 am

Wannatone,

Sorry, it is NOS RS board and it is a finite source, I have some more new sheets, but I have more amp builds booked than board !
I may even have to resort to reclaiming used board and drilling out the turret tags. Unfortunately RS have run out of the board, they still have the tags, but they are expensive, as is most of RS's parts and components.

It was actually the board used to build the first Mar***lls. It comes in a sheet 27 X 21 holes and is cut into three pieces to make three boards. It is nice to work with and obviously the turret tags fit perfectly.

I suppose I will end up using drilled plain board one day. On the other hand a CNC machine could knock a replica of the RS board up easily.

Steve UK

dboul · Post by **dboul** » Mon 02/23/04 2:48 am

Plexi wrote:"""So at the moment stevesuk is in front! """

Don't forget, Graydon is in there too, hes in his secret lab,sneaky devil,he pops up stuff like red mini stacks,offsets and lots of stuff you never know of..lol:) And hes been working on a 36 too.. As i'm sure some others like Dan B. are doing these .
Richie

Richie, Richie, Richie . . . .how did you know?!?!

Yep, me and my partners (members here who will go undisclosed until they're ready to admit it

) are working on a two versions of the 36watter as well. A stock one and a "creative" one.

We've added a couple of JMI inspired "twists" to it on one channel . . . .

The other channel is pure 18 watt style heaven with more juice of course!

We've got a couple of really neat things we're experimenting with as well as custom Iron from Mercury. Can't wait!!

We'll show you the whole thing when it's finished!

Ballz · Post by **Ballz** » Thu 03/04/04 3:27 am

Hmm...seeing the board with the stuff for the 36W and "the 125 ohm/5W under the board" makes me wonder if it would be wiser to mount the 125:s totally off the board. The heat these buggers generate is not to be disregarded, and I think you wonÂ´t have space to ventilate the 125:s (they need a bit of standoff/free air +airflow around them) if they are stuck under the board. Maybe you could use the heatsink variety of 125:s, and bolt them to the chassis. That would be a neat way to get the temperature issues sorted, while saving space on/under the board. More expensive, yes, but sortof hi-tech also

Personally, I will build a preamp/PI board only, and keep all the power section components mounted directly on the power section with a ground bus between the tubes (above the sockets), and solder points/supports between the tube pairs. If itÂ´s good enuff for the AC30, itÂ´s good enuff for me.

/Richard

stevesuk · Post by **stevesuk** » Thu 03/04/04 4:01 am

Richard,
I have used the RS 10 watt metalclad, the type with cooling fins, they have a large surface area to dissipate heat and should not even get warm. They also have mounting lugs which also help to dissipate the heat.
This means they could easily be bolted with very small bolts to the chassis.

I wouldn't recommend using ceramic etc.

Progress has halted, still wating for my transformers to arrive.

Steve Uk

Ballz · Post by **Ballz** » Thu 03/04/04 4:49 am

Yes, THATÂ´s exactly what I wanted to point out (mainly to newcomers) - use proper resistors that bolt onto the schassis, and donÂ´t cram ceramics into tight spaces...

I think I have suitable trannies here already, I will be using the innards of an old Klemt Echolette M40 PA amp (4xEL84) that is totally over the repair/restore edge cosmetically, but electronics are OK.

Good luck building, and see you down the road, then!

/Richard

Post by **Plexi** » Thu 03/04/04 8:01 am

that is a good idea,if useing the ceramic type.. and keep the cap away from the resistor as much as you can.
The board i think i'll be useing is a keystone..kinda proto type smaller baord,and it has turrets. I was thinking of moveing the cathode resistors to a seperate board at the end,by themselves.. I guess you could also use One big resistor for all the cathodes,like some other amps do.
And use a bigger wattage helps keep them run cooler..ha a small fan wouldn't hurt either. But the resistors Steve is useing,are very nice,and would work on a board,a very good idea. my holdup has just getting the time to work on things..But i do have all the parts i need. And have started figuring how i want to mount the trannys..the board i have loaded is a stock type amp.. but i think i'm going to change it to another type amp i want to build. It will have an 18 trem tone channel..and Somewhat Trainwreck as a TMB.. Started punching holes in the chassis,and its drawn out for the front. Other parts should be here today. So I should be able to get more things done. I'll post a pic when it looks more like an amp..lol
I do have the head cab too,and tolex.

Richie

Ballz · Post by **Ballz** » Thu 03/04/04 8:26 am

Richie, when looking at the power amp design, please donÂ´t repeat the mistake VOX did - using one resistor and one cap for 4 tubes.. Split the power section into individual tubes, not even pairs, from the start - that opens up a possibility to pull/switch out 2 tubes from the circuit for less power. Also, it opens up for proper bias adjustment of every individual tube in the power amp.

just 0.02 Euro (but cents, too)

Cheers /R

Post by **Plexi** » Thu 03/04/04 9:20 am

I have using 2 in mind,and on my board..And Also suggested to Steve to use seperate resistors.. But when it comes to more than that,this build is getting tight for the chassis i have,so 2 is what i'll be useing..
I sit, and did alot of tranny placement,and thinking, before i settled on which way i wanted them.. I also have 2 single turret strips,which will have the middle open for extra air circulation,to mount the cathode resistors on..
I've went through all my parts, and measured the resistors and caps..plus some old weird ones in some spots. And for anyone useing a cathode resistor,for any of these amps. its best to measure it,i have a bunch of 125ohm and some measure 118.. or lower.. And this is pretty important,or you'll cook some tubes..

Whats that saying..minds think alike..lol

Richie

Post by **zaphod_phil** » Thu 03/04/04 10:14 am

Ballz wrote: just 0.02 Euro (but cents, too)

I thought Sweden sensibly decided to stay out of the Euro system...

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First pic of 36 watt board ?

First pic of 36 watt board ?