I've made a start :) 50w #102

norburybrook · Post by **norburybrook** » Sun Jan 25, 2015 10:51 pm

well it makes a noise.............

the relays aren't working at all the tone controls are not doing anything except for the treble which seems to be acting like a volume?????????

I had a feeling the relays were going to be my Waterloo.

whats the first thing for me to check with the relays tomorrow? I was balancing Martins layout with the boards I had as they're slightly different.

see pic

I'm off to bed now, tomorrow is another day.

Marcus

martin manning · Post by **martin manning** » Mon Jan 26, 2015 12:45 am

I had another look and I believe I had the transformation done correctly. Here's another mark-up with your photo reversed to show the boards as viewed from the top side and updated for "no R/J." Check your connections against this and see if you see anything amiss.

norburybrook · Post by **norburybrook** » Mon Jan 26, 2015 10:05 am

THanks Martin, looking at that I can see I've wired mine completely differently as I used the ceriatone layout as well as your original one.

My relays are 5v and I've got 4.9v coming from the regulator however I've got 18v coming into the regulator from the transformer/board, that seems like the a lot to me as the regulator is doing an awful lot of work to get from 18 to 5 v or is that OK?

Just checking the transformer info again and it should be putting out 6v , don't know why I'm getting 18v coming off the relay board.

Marcus

martin manning · Post by **martin manning** » Mon Jan 26, 2015 10:27 am

I'm using Tony's layout. Your OD board looks like the Ceriatone, but I have shown it wired like Tony shows with OD on when the relay is energized.

The relay supply is using a voltage doubler. Is the relay transformer center tapped? If so you can just use half of the winding into the rectifier and cut the DC going into the regulator in half.

norburybrook · Post by **norburybrook** » Mon Jan 26, 2015 10:43 am

martin manning wrote:I'm using Tony's layout. Your OD board looks like the Ceriatone, but I have shown it wired like Tony shows with OD on when the relay is energized.

The relay supply is using a voltage doubler. Is the relay transformer center tapped? If so you can just use half of the winding into the rectifier and cut the DC going into the regulator in half.

No there's no center tap on the relay transformer.

http://uk.mouser.com/Search/ProductDeta ... 553-F-313X

is the regulator going to be ok taking 18v down to 5v? It's obviously going to be putting out a lot of heat but that will go through the chassis as a heat sink, just worried it might melt the solder if it get to hot.

Marcus

martin manning · Post by **martin manning** » Mon Jan 26, 2015 11:04 am

norburybrook wrote:Is the regulator going to be ok taking 18v down to 5v? It's obviously going to be putting out a lot of heat but that will go through the chassis as a heat sink, just worried it might melt the solder if it get to hot.

It should be ok. The power dissipation depends on the current draw, and you are not asking for much powering a couple of low-current relays and LED's.

ToneMerc · Post by **ToneMerc** » Mon Jan 26, 2015 11:11 am

norburybrook wrote:
is the regulator going to be ok taking 18v down to 5v? It's obviously going to be putting out a lot of heat but that will go through the chassis as a heat sink, just worried it might melt the solder if it get to hot.
Marcus

Not a bad idea to get in the habit of reading data sheets. If you look at the data sheet for just about any LMxx linear regulator, the max input voltage is around 36-37 volts.

TM

norburybrook · Post by **norburybrook** » Mon Jan 26, 2015 11:32 am

ToneMerc wrote:
norburybrook wrote:
is the regulator going to be ok taking 18v down to 5v? It's obviously going to be putting out a lot of heat but that will go through the chassis as a heat sink, just worried it might melt the solder if it get to hot.
Marcus
Not a bad idea to get in the habit of reading data sheets. If you look at the data sheet for just about any LMxx linear regulator, the max input voltage is around 36-37 volts.

TM

LOL point taken, I feel duly chastised

Got to do some proper work today in the studio ( mixing a new album for http://www.lucindadrayton.com/ ) so I'll get onto this in the evening.

Not looking forward to getting those relay boards out and rewired.

Marcus

ToneMerc · Post by **ToneMerc** » Mon Jan 26, 2015 1:22 pm

norburybrook wrote:

LOL point taken, I feel duly chastised

Marcus

Marcus, no need to feel chastised and wasn't intended as such, just a friendly tip.

TM

norburybrook · Post by **norburybrook** » Mon Jan 26, 2015 4:08 pm

ToneMerc wrote:
norburybrook wrote:

LOL point taken, I feel duly chastised

Marcus
Marcus, no need to feel chastised and wasn't intended as such, just a friendly tip.

TM

no problem. I am eternally grateful to everyone here for their help, especially my mentor Martin, you'll make an amp builder of me yet

now back to my mixing.

Marcus

norburybrook · Post by **norburybrook** » Mon Jan 26, 2015 8:10 pm

Martin,

what exactly do you mean by:

overdrive IN/OUT and CI out on the relays?

Marcus

martin manning · Post by **martin manning** » Mon Jan 26, 2015 8:26 pm

OD out is the output from the OD section, which would be the Ratio pot wiper.

OD in is the input to the OD section, which is the resistor/trimmer pot going to the V2a grid.

Cl out is the output from the clean section, which is the cap coming from V1b's plate.

Charlie Wilson · Post by **Charlie Wilson** » Mon Jan 26, 2015 8:29 pm

Marcus,
CL out or clean out goes from the .05 V1b coupler to your relay. Overdrive in goes from your relay to the 220k OD entrance resistor. Overdrive out goes from your OD volume(ratio) to the relay and MV3 goes from the relay to your global master volume. OOps Martin got there first. Marcus don't get frustrated. This is the part of building were you carefully think through the issue, solve it, and learn something.
CW

norburybrook · Post by **norburybrook** » Mon Jan 26, 2015 9:15 pm

Charlie Wilson wrote:Marcus,
CL out or clean out goes from the .05 V1b coupler to your relay. Overdrive in goes from your relay to the 220k OD entrance resistor. Overdrive out goes from your OD volume(ratio) to the relay and MV3 goes from the relay to your global master volume. OOps Martin got there first. Marcus don't get frustrated. This is the part of building were you carefully think through the issue, solve it, and learn something.
CW

indeed , I was just saying to friend today, when my JTM45 didn't work first time , the week I spent trouble shooting was such a great learning experience I'm glad it worked out that way.

At the time though it's quite frustrating

thanks for the replies guys, back to the iron..............

M

norburybrook · Post by **norburybrook** » Mon Jan 26, 2015 9:35 pm

Ok wired up exactly as the picture and still not working.

should I hear the relays switch if they're working?

also the amp is very quiet and thin, there's a faint high pitch background noise and if I switch the impedance selector from the 16ohm its now at, to the 8 and then 4 it get louder as I hit the 4 ohm. the NFB is connected to the 4 ohm so I presume it's something to do with that.

is this my output primaries? I remember the squeal being quite loud with my last build when I got them the wrong way round.

Marcus

Tube Amp Archive

I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102

Re: I've made a start :) 50w #102