pre amp power

[Atk1d]

Hi every one I am visiting my brother who has just finished his SSE, I've checked it over all appears to be good and wired correctly, The driving tubes, Rectifier tube light as they should, pre amp (12at7) seems to have zero power.

will try to apply photos

Any help trouble shooting would be great.

Thanks to all who respond

 

[Atk1d]

Pre amp power- no sound

Well after reflowing all solder connections pre-amp section has power, but have no sound, can not find b+ on any of the tubes, or the opt (red wire)

opt= edcore cxe25-8-5k
pt=edcore xpwr 120 ( red at board 375v, yell, brown at board 6v, blk/red,wht/brown)

have amp wired for ul mode w cathode feedback.
please help
Thank you to all again.

 

[nigelwright7557]

Check your power supply for volts.

 

[Atk1d]

power supply is 120 in
red wire are 375v
yellow wire 5v
Brown wire 6.3v
two others black/red centre tap Of primary350 and white /brown 6.3 both not used

I was reading another post where the ccs's were bad and these may be bad also as G=.3 k too and A is 425

new ccs's are on order will wait. I hope this works as my brother is frustrated thus far.
Also still can not locate a B+ reading across any pins (3) on any tube or from opt(red wire)

 

[Atk1d]

well after some effort, we switched out boards, and b+ is Right side 235-240 left side 845
still no sound.......... volume pot is alps 100k, all connections verified ohms climbs when volume is turned up.
input signal same....as far as we can identify some help here would be good too
need a little help identifying where loss of signal could be happening
Also why the B+ is so different from side to side
we've checked the schematic but need to know what values should be at given points when power applied. Should help isolate bad parts.

to retstate... pt = xwpr025 350-0-350 decor
opt = cxe 25w-8-5k also from decor

power choke (edcore)
aux supply cap = clarity cap tc45uk700v 1306b

Thank you to all who respond

 

[Atk1d]

no sound

following up with my other post here is a picture
I have connected the ct of 370v from pt (is inclusive with photo) which makes the rectifier glow red hot so I have disconnected until I learn different.

note the rectifier is a china made 5z3pa 73iv or 731v
for now its all that is available, a sovtek 5ar4 is on order

This board is of the new style, cl140 and two diodes are in place

Please help
should the ct be used?
where should we check for loss of signal

 

[zxx222]

Did you read sse wiring diagrams page on tubelab webpage? First picture clearly shows that you should use center tap of your high voltage winding. Read everything carefully. Without center tap you have 700 volts across high voltage secondaries.
According to your rectifier datasheet first cap maximum is 4uF and SSE first cap is 47 uF. I am very surprised that it did not explode when you switched on amp. Try your best to do everything according to sse manual - It is not so difficult.

 

[Atk1d]

zxx222 Thank you for responding, He's very good at practicing medicine(my brother) sadly not so good with electronics( strange our Father was an electronics guru(like George)) so I have decided ( just received) a new board going to populate it test with my working amp and ship back to him.
Also I have advised him to order one or more sovtek 5ar4 tubes I use one and love it.
The center tap was used on the previous board made the rectifier plates glow red, something was amiss either the rectifier used was incorrect (most likely) or something soldered in the wrong place. All parts came from Mouser so the unlikely hood of bogus parts seems well........ unlikely. I spent three days of my vacation trying to figure it out. ultimately no sound from either board used
One last try with new board, I hope it works or out in Nova Scotia there is going to be some new debris in the ocean ( kidding)
Thanks again

 

[zxx222]

Use 5ar4 rectifier. Check u10 and u20 - you soldered them on other side of board and it seems that in wrong direction. Look at board photos of other sse builders on this thread and you will see what I mean.

 

[Atk1d]

I know it appears that way but in fact they are in correctly, and really at this point it does not matter, that board as stated, has been abandoned.Also the sovtek 5ar4 will be used as stated
But thanks anyway.

 

[PDL]

Do you have a choke installed?

 

[Atk1d]

yes there is a choke installed, its from edcore, I am no longer visiting so I am not sure of the model number, or ohms rating I can tell you its large.
There was some soldering issues and the ccs components may have been damaged during install, but no worries I have received the new board will populate it, test it the ship to my brother for installation into the chassis have posted.

Thanks though