the Poor Man 660 support thread

[skal1]

  nice one  this will be my third attempt on this psu if this don't work i am going point to point old school

cheers

skal1

 

[dingo]

R1 should be 10W 50R  - 100R and R2  2W 150K - 75K depending on your situation. Tweak the values so that you have 310V - 320V going into the regulator under full load meaning when the tubes are conducting/working or whatever you wanna call it.

hello still having problem with  the high voltage rail
with the analag mod  both channel connected  all tube voltage reach 245v than start floating from 210 to 190??? ???
can see the meters moving  with the voltage  floating
if i use just one channel it work  and sounds great
do not matter which channel  i use... but just une chanell...
so my idea is to build a second psu for the other channel maybe  a semplified version without all the small trnstrs
just the high voltage rail (245+136)v
build the  245vpsu rail like the 136v rail on the schematic  it is possible?

 

[radiance]

hello still having problem with  the high voltage rail
with the analag mod  both channel connected  all tube voltage reach 245v than start floating from 210 to 190??? ???
can see the meters moving  with the voltage  floating
if i use just one channel it work  and sounds great
do not matter which channel  i use... but just une chanell...
so my idea is to build a second psu for the other channel maybe  a semplified version without all the small trnstrs
just the high voltage rail (245+136)v
build the  245vpsu rail like the 136v rail on the schematic  it is possible?

Maybe start with another toroid just for the second heater....Since you're using the slow start heater boards you'll have to do this anyway.
The toroid you have now is not able to power both slow start heater boards.
Also, AFAIK apart from the heater secondaries this toroid is perfectly capable to power two channels.

 

[dingo]

hello radiance
my slow start heater have is own transformer 100va  9v(lot of juice)  both slow start have sep. bridge rect. not using rondo 9v section
transf any more .
same with relays lamp and scamp booster have separate power supply pcb with 24v (m-nats one )and  dedicated transformer
the rondo is just driving +17v -17v and the high voltage(245 136 v)
so  is just the high voltage failure !! :-\

 

[radiance]

hello radiance
my slow start heater have is own transformer 100va  9v(lot of juice)  both slow start have sep. bridge rect. not using rondo 9v section
transf any more .
same with relays lamp and scamp booster have separate power supply pcb with 24v (m-nats one )and  dedicated transformer
the rondo is just driving +17v -17v and the high voltage(245 136 v)
so  is just the high voltage failure !! :-\

Sorry, I did not know that....

 

[radiance]

hello radiance
my slow start heater have is own transformer 100va  9v(lot of juice)  both slow start have sep. bridge rect. not using rondo 9v section
transf any more .
same with relays lamp and scamp booster have separate power supply pcb with 24v (m-nats one )and  dedicated transformer
the rondo is just driving +17v -17v and the high voltage(245 136 v)
so  is just the high voltage failure !! :-\

Have you tried powering two channels with both only one 5687 inserted? You might want to re-read Kevin's posts in this long support thread...

 

[dingo]

radiance!
yes have tried every combination and same scenario
now  am doing some experiment with the power supply  some diode for protect q4 and  some cap around q2 etc..etc..
will tell you soon!!

 

[dingo]

hello!!

have solved  all the problem on high voltage rail...
sounds great no hum no noise ...fantastikkk!! ;D
special thanks to Pier Paolo Abbate  ... everybody  on this thread
her some pic  of my unit ;D

 

 

[skal1]

how do you solve the Ht problems


cheers

skal1

 

[radiance]

Yeah....what was going on there?

 

[[silent:arts]]

Great you (and Pier) sorted the problems out.

For sure we all are curious what Pier did

 

[ppa]

thanks Dingo, even for putting up with me on phone

if the PSU is very good is because the original schematic is very good , I have only added some components.

here there are the mods i have suggested to Dingo.

IMPORTANT: ATTENTION ! to do this modifications has risks of electric shock, fire and other very dangerous damages, I am NO responsible on this my schematic I have posted here in any case! Use this schematic at your own risk!





edit: schematic corrected

 

[ppa]

the first schematic had an error , now is corrected, c7 and c8 must be at the +245V out

C6 can be higher than 220pF, D12 is optional with C6=220pF  

 

[radiance]

Ok, so basically Dingo contacted PPA who suggested some mods on the existing PSU after which ALL Dingo's problems were gone???

Way to go PPA!!

 

[dingo]

hello! radiance
yes  basically have done the ppa suggested mod 
on the existing psu  under the pcb  and now my high rail voltage are ok
have removed all the mods done before
6.3 v have separate toroidal 100va ,and scamp booster have 24v from proper psu and toroidal

 

[Silvas]

I just had an idea. It is possible to use another kind of tubes in the sidechain ? of course via the appropiate adapter ? i´m thinking on something that run less hot and draw less heater current from the PT...anyone has tried something like this ? Just don´t shoot me if it´s not quite a good idea !

I´m currently running my PM on 1 5687 per channel, and my PT is hot.

 

[mich]

yes,these sc tubes are almost like 6L6's in power consumption and heat...if you are doing fine with one tube im prety sure 2 x 12bh7  will do the job...but im no expert..

 

[Silvas]

yes,these sc tubes are almost like 6L6's in power consumption and heat...

Exactly !

 

[kazper]

I just had an idea. It is possible to use another kind of tubes in the sidechain ? of course via the appropiate adapter ? i´m thinking on something that run less hot and draw less heater current from the PT...anyone has tried something like this ? Just don´t shoot me if it´s not quite a good idea !

I´m currently running my PM on 1 5687 per channel, and my PT is hot.

it's been mentioned before that if you powered the 5687 with 12V heaters over the 6.3V it would help since were paying a price to drop the voltage on that power resistor anyways. I'm also thinking that most of the power transformers are running close to there 100% rating and should have been specified larger with some breathing room.

Regarding the Tube swap:
12BH7 is not a exact replacement, which I'm sure your aware of, but if your willing to adapt you might want to kick a pair of 6N6P (Russian 6H6N tubes). The JJ ECC99 is also in the same realm.  For an adapter idea check out this, but if It was me I would bush the copper with a grommet.

Take a look at the E182CC,7199 as direct pin compatible replacements that draw slightly less power.

 

[Silvas]

it's been mentioned before that if you powered the 5687 with 12V heaters over the 6.3V it would help since were paying a price to drop the voltage on that power resistor anyways. I'm also thinking that most of the power transformers are running close to there 100% rating and should have been specified larger with some breathing room.

Good idea. This will take some work, tho. The 6bc8 (or 6n5p) will need 6.3v heaters anyway, right ?