1176 Plosives: looking for Rev A schematic or high res internal shots

[Biasrocks]

I am aware that mine is a rev B, but Are you sure that the Rev B didn't have the dual FET? My schemo shows it, and  q4 is socketed, as are the other FETs....

Hi Chuck

I'm not sure which schematic you're referencing.

REV B as noted in the 1176 docs from the JBL site shows this note for 1176 "B".

"Two transistor input amplifier"

The REV B schematic shows this as well.

Mark

 

[la-2a]

Hi, I uploaded the scans.  1176_125 is serial 125,  1176_293 serial 293.

here the link : http://yfrog.com/dy11761251jx

Hope I could help and all is O.K. Pictures will follow soon when I am back in the studio

I was just thinking about recapping the units. What would you guys do.?? Keep it original.??

cheers

 

[Biasrocks]

Hi, I uploaded the scans.  1176_125 is serial 125,  1176_293 serial 293.

here the link : http://yfrog.com/dy11761251jx

Hope I could help and all is O.K. Pictures will follow soon when I am back in the studio

I was just thinking about recapping the units. What would you guys do.?? Keep it original.??

cheers

Thanks for those!

You should definitely recap it, you need only do the electrolytics and tantalum capacitors.

Everything else, leave as is.

Mark

 

[la-2a]

Hi, here the pictures of one of the units .Serial 293 labeled B-Version. The other one is
is older and has no LN modification. It should be the real A-Version.

Cheers

 

[la-2a]

another one SN:293 -B

 

[la-2a]

ONCE MORE

 

[barclaycon]

la-2a
Thanks for the schematic scans - some of the clearest I've seen.

When you get chance can you do some pictures of your 125 unit, like the ones you've done for the 293.

They would be extremely useful.

Thanks again.

 

[ChrioN]

This thread confuses me  ;D
I hope someone makes all the hard work for the rest of us. 

 

[la-2a]

Hi here  we go, here are the pictures of my Bluestripe Serial Nr. 142 ....sorry not 125 like It was written on the schematics , but not that far away: And it is  an original REV A.! .

I  will make some postings now here because of better resolution.

cheers

 

[la-2a]

next one

 

[la-2a]

the pushbottons

 

[la-2a]

and the serial..........

I hope I could help again ........this forum gave me so much.....

thank you .

 

[Rob Flinn]

LA2a thanks for that..  You're pics are very useful. 

 

[Rob Flinn]

From what I can see so far it seems to have all the resistor values of the Rev "A" diagram.

By the way most of the blue electrolytics on the board look a little past their sell by date.  Have you tried testing them with an esr meter ?

 

[la-2a]

From what I can see so far it seems to have all the resistor values of the Rev "A" diagram.

By the way most of the blue electrolytics on the board look a little past their sell by date.  Have you tried testing them with an esr meter ?

You will not believe it. I checked them some time ago with my Tenma LCR Meter and the values were inside the tolerance.
Compared to my REV A Clone it has not that open end, but I love them how they are.
But your´re right. I got to recap the units soon  . I just don´t know where to buy that big sized
PSU Caps 

cheers

 

[Rob Flinn]

From what I can see so far it seems to have all the resistor values of the Rev "A" diagram.

By the way most of the blue electrolytics on the board look a little past their sell by date.  Have you tried testing them with an esr meter ?

You will not believe it. I checked them some time ago with my Tenma LCR Meter and the values were inside the tolerance.
Compared to my REV A Clone it has not that open end, but I love them how they are.
But your´re right. I got to recap the units soon  . I just don´t know where to buy that big sized
PSU Caps 

cheers

D

Does your Tenma LCR meter test ESR (equivelent series resistance)?  That is really the property that is important.  Many caps can spec near to the correct capacitance value but their ESR is out of spec.  TMostly I notice that the smaller values are most problematic.  You may find that the larger PSU caps are ok.


Also how did you populate you blue stripe clone, which diagram did you use ?? DOes it sound like your originals ??

 

[la-2a]

[/quote]
Also how did you populate you blue stripe clone, which diagram did you use ?? DOes it sound like your originals ??
[/quote]

I used  the complete Hairball Kit inclusive  Altran C-3837-1 and EA-5002 transformers, mnats  rev A board, the orange drop 1mf caps.

Resistor values pushbutton now: 180R,470,470,1.5K ,10M, 56K, 56K, 68K. (130K changed to 68K)
R46 = 22K.
The reason why I went to this threat was, that I was not satisfied with the threshold and the ratios.
So I went to compare the pushbutton values and to make some changes.  (I already work on that. )

Than I remembered that I got that schematics somewhere and finally I posted them here and made the pictures to come closer to the real one. But who knows maybe they were new the same like my clone.
What I can for sure say is that we are very very  close to the real ones.
Sure there is a difference but I think I cannot seriously compare them until I have not recapped the old units. Now my clone has more top end and smooth . The originals act a bit more harder.......they are more pumping with slow attack and release values.
Finally I can say that in a couple of days when all work is done. I will post the results.

Does somebody know where I can get those big PSU caps .??

cheers

 

[barclaycon]

Thanks very much for the pictures la-2a.
Very useful and much appreciated.

 

[Biasrocks]

Thanks for the pictures La2a, very cool.

Any chance you could take a picture of the Attack and Release pots?

Mark

 

[Neeno]

Hi La-2a !
Great pictures, thank you so much !

You can source the caps from http://www.banzaimusic.com/Electrolytics/ or www.tubetown.de
I've got some Sprague Atom will fit.

Thank you very much again !