the Poor Man 660 support thread

[skal1]

Hey , can anyone help me with this heater resistor  thingy , ok know matter what resistor i connect to r15 i do not seem to get a voltage drop for the heater supply , what  am i doing wrong ?

regards


skal1

 

[[silent:arts]]

Hey , can anyone help me with this heater resistor  thingy , ok know matter what resistor i connect to r15 i do not seem to get a voltage drop for the heater supply , what  am i doing wrong ?

measuring without tubes in ?

 

[skal1]

yes without the any signal boards connected


regards

skal1

 

[lolo-m]

No tube = no heater current = no voltage drop thru R15 = no heater voltage change

 

[skal1]

That what i thought , so no load means no voltage drop .If i connected two 8v 2.5A bulbs in parallel to the heater out put  would this simulate the two signal pcbs?

@lolom


regards

skal1

 

[lolo-m]

Yes it will simulate it, but with an error... I don't think they will take 2,5A if the voltage drop thru R15 tends to give you 6.3V... You can measure the current anyway thru R15 with the ohm law I=U/R15 to know if you're close to the ideal value for R15 or not...

 

[lewilson]

Maybe for the next batch of pm660 pc boards you can put a little more room for transisor sockets for q1 q2 and q3.  Many thanks

 

[skal1]

ok just hooked up 1 chan of the poor man but it does not sound right , i have checked the supply to the board with out tubes in and that is ok .


245=250

137=139

the 17v rails are ok too the heater voltage is 6.4

With tubes in i am getting really low voltage on the 245v and 137v  so 245v equals 40v and 137=20v every other voltage is ok , bacisally under load strange things are happen  any clues.javascript:void(0);

regards

skal1

 

[veermaster]

I think there were some similiar problems with another members unit, you should check the previous posts.

 

[skal1]

Hey veermaster that post has no conclusion to their  problem  it seems funny that the psu is ok  without the signal board connect and ok with signal board connected without tubes in ,this makes think that irf840/820 can not handle the load of the 4  tubes properly , so tomorrow i will try subing the 820 for the 840 and see what happens then.

regards


skal1

 

[veermaster]

I thought they solved the problem but I didn´t really follow since I was lucky enough to have a working PSU.
Good luck!

 

[MartyMart]

I'm sure that Volker mentioned that 2 x 840's may help.

MM.

 

[RedNoise]

to remember for all people having PSU problems:
use IRF840 on both places (Q4 & Q5)
doesn't make sense to order one IRF820 & one IRF840 anyway

 

[skal1]

;D yes yes the beast lives

to remember for all people having PSU problems:
use IRF840 on both places (Q4 & Q5)
doesn't make sense to order one IRF820 & one IRF840 anyway

regards

skal1

 

[mrclunk]

yes yes the beast lives

muhahaa

Hopefully mine will soon, i just need a clear day to finish it. 

 

[[silent:arts]]

;D yes yes the beast lives

good news - have fun  ;D ;D ;D

 

[skal1]

Thanks to analog and the art for bring this project bless up , whens the tube eq comin?


regards

skal1

 

[[silent:arts]]

... whens the tube eq comin?

should have more time :-\
but it will come for sure

 

[skal1]

ok this might be a silly ? , i have injected a 0.776v sine wave in to the poor man ,which i have read is  0db so why is it that the poor man is clipping on my master meter on my o1v , i can hear the compression but with the led meter sticking at clip i can not see what happen , do i need some sort of volume control on the output or am i missing some thing.  ???


regards

skal1

 

[Moby]

ok this might be a silly ? , i have injected a 0.776v sine wave in to the poor man ,which i have read is  0db so why is it that the poor man is clipping on my master meter on my o1v , i can hear the compression but with the led meter sticking at clip i can not see what happen , do i need some sort of volume control on the output or am i missing some thing.  ???


regards

skal1

You have two controls. Input and threshold. Turn the threshold at min to achieve no compression and tune the input to have 0 db. Then you are at unity gain . Than if you turn threshold you will notice some compression at some point