the Poor Man 660 support thread

[weiss]

Hi,
Your resistor are solder wrong. You have to go from one position to the next, not from one deck to the other. Have a look at the pictures of my unit, you'll see what I mean. You have got a switch with four decks, but you need only two. Go to first thread and you will find a link to my unit with pictures.
Regards
Bernd

hmm seems like the owner before me did something wrong

 

[prescott]

Hello!

I'd like to share my opinion about this comp.
First I made it stock. It was good. Then I changed the tubes to the russian types, it was a huge difference. The next step was changing the attack and release to custom ones. It made the comp very useable.  After it a put in the SCAB, with this pimp it came to life, very very good. And the final mod was to change the input transformers to ll1676 and the output ones to Sowter 8650.
The biggest difference came after changing the trafos. No more low end distortion, rich, full sound, my best comp with this trafos. I know it is not so Poor Man, but the result is excellent!!!

Now I can push very hard the input, the crossover distortion is over...

I suggest to everybody to change the input and output transformers to more accurate ones. The edcors have very nice color I know and I like it a lot but in this application it's just not fit well.

Peter

 

[weiss]

what tubes did you use? well i actually like some low end distortion

 

[prescott]

The 6n5p types. (very important to be matched)
This is not that kind of low end distortion that you would like
Just look at a sine at 30hz...
We've just remastered some tracks with the upgraded comp, and in every track the new version was better.

 

[weiss]

Nice to hear that. I believe you. Is it possible to share some A/B? I would like to know how big the difference is ;-)

 

[prescott]

The problem is that we did not write down the settings at that time, but I can show the original master and I can make a new master with the comp and the other stuff we used on the track.
In a few days I post it!

 

[weiss]

The problem is that we did not write down the settings at that time, but I can show the original master and I can make a new master with the comp and the other stuff we used on the track.
In a few days I post it!

great! looking forward to it

 

[weiss]

Hi,
Your resistor are solder wrong. You have to go from one position to the next, not from one deck to the other. Have a look at the pictures of my unit, you'll see what I mean. You have got a switch with four decks, but you need only two. Go to first thread and you will find a link to my unit with pictures.
Regards
Bernd

thanks for your reply bernd! but the guy who sold me these pots told me, it would work for the pm670!

 

[shabtek]

they should work weiss this uses 2 resistors to form voltage divider at each step instead of a string\ladder ,  the wire that connects all resistors on one end of switch should be low\ground and the tab that connects to the joint of 2 resistors in a given step is the wiper, the other tab steps to end of the resistor not grounded and is the other end of the voltage divider

 

[weiss]

they should work weiss this uses 2 resistors to form voltage divider at each step instead of a string\ladder ,  the wire that connects all resistors on one end of switch should be low\ground and the tab that connects to the joint of 2 resistors in a given step is the wiper, the other tab steps to end of the resistor not grounded and is the other end of the voltage divider

thanks for the clarification shabtek! still i am not really sure where to make the connection to the pcb..

 

[duantro]

they should work weiss this uses 2 resistors to form voltage divider at each step instead of a string\ladder ,  the wire that connects all resistors on one end of switch should be low\ground and the tab that connects to the joint of 2 resistors in a given step is the wiper, the other tab steps to end of the resistor not grounded and is the other end of the voltage divider

thanks for the clarification shabtek! still i am not really sure where to make the connection to the pcb..

Take what Shabtek says here and look at the wiring diagram in the first post. It should make sense after you wrap your head around it.

 

[weiss]

Take what Shabtek says here and look at the wiring diagram in the first post. It should make sense after you wrap your head around it.

I am currently looking at it. The lead at the back of the switch in the wiring guide, what would be the equivalent lead in my case? (orange and brown)
Sorry for these noob questions

 

[duantro]

Take what Shabtek says here and look at the wiring diagram in the first post. It should make sense after you wrap your head around it.

I am currently looking at it. The lead at the back of the switch in the wiring guide, what would be the equivalent lead in my case? (orange and brown)
Sorry for these noob questions

The brown or orange wire is connected to the wiper position. I couldn't see where your wiper was on your switch from your photo, but should be similar to the wiring diagram. The wiring diagram shows both decks of the dual deck switch, separately. Perhaps this is where it is confusing.

 

[weiss]

That's not actually what confuses me..
i assume this is the attenuator that was sold to me: http://www.ebay.com/itm/251276160707

would it be possible with 4 poles? the resistors were pre soldered already

 

[duantro]

That's not actually what confuses me..
i assume this is the attenuator that was sold to me: http://www.ebay.com/itm/251276160707

would it be possible with 4 poles? the resistors were pre soldered already

I think you can make these work.  I'd start from scratch here. Remove all of the resistors on your switches. You should be only using 2 decks, instead of the the 4 that appear to be here. I assume the wipers are on the back? Then get your continuity meter out and decipher how the pins  are laid out, so you don't have to do it more than once! Then get your resistor values from the calculator.

 

[weiss]

I think you can make these work.  I'd start from scratch here. Remove all of the resistors on your switches. You should be only using 2 decks, instead of the the 4 that appear to be here. I assume the wipers are on the back? Then get your continuity meter out and decipher how the pins  are laid out, so you don't have to do it more than once! Then get your resistor values from the calculator.

thanks for your advice, duantro. there are two connections on the back (two screws). should these be the wipers? last week i bought some uraltone 2x24 switches. i think i will use them and dump the other four. so i don't have to desolder everything.

 

[duantro]

I think you can make these work.  I'd start from scratch here. Remove all of the resistors on your switches. You should be only using 2 decks, instead of the the 4 that appear to be here. I assume the wipers are on the back? Then get your continuity meter out and decipher how the pins  are laid out, so you don't have to do it more than once! Then get your resistor values from the calculator.

thanks for your advice, duantro. there are two connections on the back (two screws). should these be the wipers? last week i bought some uraltone 2x24 switches. i think i will use them and dump the other four. so i don't have to desolder everything.

I'd ust use the uraltones. Put a meter on your wiper and check for continuity on the pin that corresponded with the switch position.

 

[served]

Hi.

I have a strange issue with my previously working 660.
Its built like it should.
It compresses and works like it should, but.
There is strange distortion in the sound if I push it.
If I feed it with sine, I get a crossover-distortion-like picture.
What could cause it?
I have biased the trimpots like they should be. Changed the V1 and V2.
All the supply outputs have good DC values.


EDIT: I have read some pages and going to change the T2 , lets see what happens. Also, I will test some other tubes.


Have changed T2 to Carnhill VTB2291. No change.
Changed the T1 to VTB2381M, some changes, but not where I would like it to be.
Changed the 6BC8 tubes. Sound is more open, but no change in distortion.

I have added a picture where I Tested 4 good tubes. Not much changed involvin the crossover. Only slight changes in the amplitude.


Next:
1) Remove sidechain (desolder the T3 connection)

A small improvement but not perfect. I get more clean room on the way.
But distortion depends on the Time value even if T3 is not recieving any signal.

2)I will add a toggleswitch to switch between Crainhill and Edcor transformers (T1 ; T2). To see how this affects the picture. But I am sure there is not much improvement.

 

[served]

Hi.

Still have not figured this out.
But I have some questions.

What should the voltage be on when measuring one leg of R5 to Ground. And the second leg of R5 to ground.
They should be the same voltage.

But what should the value be?
Could anyone measure it for me?

 

[Freddy G]

5 years! I have slowly been building this thing for 5 years now. I had it to the point recently where it worked....rock solid, no problems.

So I ordered a front panel for it and I thought I would just finish off a few last minute touches.

As I was wiring in a switch for the meter to go between gain reduction and output , my troubles started.  The right side worked fine, but the left side did not. It showed very little gain reduction for a minute then the whole thing got much lower in volume. I thought OK....I have one good working side so surely I can figure out what the difference is.

No.

After trying a few things, now both side have very little gain, not much bass and generally crappy sounding!

All my voltages seem correct. Can anyone help me? I'm going to lose my mind with this thing.  I just want to finish it and start using it....when it was working it sounded gorgeous!