Neeno

Hi guys.
I'm looking for a readable version of the 1176 rev A schematic.
I can't read the value of R11.
An high resolution interior shot would be ok too.

If you own an original rev A (not AB or B) please send me an email.
I'm trying to solve the plosives problems with all ratio buttons in.

Thanks in advance.
« Last Edit: January 09, 2010, 06:13:23 PM by Neeno »
Neeno
Quote from: "CJ"
Hippies would never  kill a Llama. They might have dope crazed sex with it, but never kill it.
Quote from: "CJ"
REMEMBER, A FLUTE WITH NO HOLES, IS NOT A FLUTE, AND A DONUT WITH


emrr

Re: Looking for: 1176 rev A schematic or high res internal shots.
« Reply #1 on: July 10, 2009, 05:34:57 PM »
Is the rev A repro schematic of no help?   I see the exhaustive UREI manual download is illegible on that value.
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounded g

Neeno

Re: Looking for: 1176 rev A schematic or high res internal shots.
« Reply #2 on: July 10, 2009, 05:39:16 PM »
Hi Doug,
yes, the repro is referred to a different schematic.

Neeno
Quote from: "CJ"
Hippies would never  kill a Llama. They might have dope crazed sex with it, but never kill it.
Quote from: "CJ"
REMEMBER, A FLUTE WITH NO HOLES, IS NOT A FLUTE, AND A DONUT WITH

Rob Flinn

Re: Looking for: 1176 rev A schematic or high res internal shots.
« Reply #3 on: July 10, 2009, 07:30:27 PM »
neeno I'm with you we need to work this out.   Do you get the pumping thing on all in mode ??
regards Rob

Capital letters.  The difference between helping your uncle Jack off his horse, & helping your uncle jack off his horse ........

edanderson

Re: Looking for: 1176 rev A schematic or high res internal shots.
« Reply #4 on: July 11, 2009, 01:00:55 AM »
i don't understand the connection between the all buttons in mode and R11, which is attached to Q2 (the first signal FET in the preamp)?  R11/R12 is a bit fuzzy but i would say it looks like 10k/1k in the original and 9.1k/2.2k in the rev A.  this is a pretty minor tweak and doubtful the cause of your issue.  i'd rather look at R18 and R22 or anything having to do with the sidechain when all the ratio resistors are all bypassed.

ed


Neeno

Re: Looking for: 1176 rev A schematic or high res internal shots.
« Reply #5 on: July 11, 2009, 06:33:47 AM »
Hi Ed !
Thanks for your reply !
You're right, R11 and R12 wouldn't solve the plosives problem.
What I'm doing now, is following the Rev A schematic.
I still have to compare the sidechains of the original and the rev A, but it looks like they didn't modified anything there.
The major differences I found are in the preamp section and the ratio board resistors.
Probably stuffing the board following the rev A schematic would solve the problem.

Do you have more readable rev A schematic ?
Thanks for your help.
Neeno
Quote from: "CJ"
Hippies would never  kill a Llama. They might have dope crazed sex with it, but never kill it.
Quote from: "CJ"
REMEMBER, A FLUTE WITH NO HOLES, IS NOT A FLUTE, AND A DONUT WITH

Neeno

Re: Looking for: 1176 rev A schematic or high res internal shots.
« Reply #6 on: July 11, 2009, 08:34:38 AM »
neeno I'm with you we need to work this out.   Do you get the pumping thing on all in mode ??

Hi Rob ! Thank you.
Well, I don't have any problem with the brit mode.
But that's because I'm testing the rev A board inside a rev D I already built.
Try to use the values shown on the JBL rev A schematic for the ratio board, I'm 99% sure it will fix the problem.

Report back what you find out !

Now I'm trying to figure our all the parts that have been changed from the original 1176 to the rev A.
It's referred to the schematics, so it would be great if someone with a real rev A can help up sort this thing out.

The bright side of the story is that probably Mnat's rev A could be stuffed in 2 ways, isn't this just great ?  :)

Cheers,

Neeno
Quote from: "CJ"
Hippies would never  kill a Llama. They might have dope crazed sex with it, but never kill it.
Quote from: "CJ"
REMEMBER, A FLUTE WITH NO HOLES, IS NOT A FLUTE, AND A DONUT WITH

Rob Flinn

Re: Looking for: 1176 rev A schematic or high res internal shots.
« Reply #7 on: July 11, 2009, 08:40:13 AM »
Neeno.

I used the ratio board values that are supplied with the pcbs the Hairball supply.  They are different from the rev D values, in accordance with the diagram the Mako supplies.  If you are using the rev D values then both scenarios have been tried ??

I keep thinking that backing off the gain in the side chain might be useful maybe decreasing the value of R46 ???
regards Rob

Capital letters.  The difference between helping your uncle Jack off his horse, & helping your uncle jack off his horse ........

Neeno

Re: Looking for: 1176 rev A schematic or high res internal shots.
« Reply #8 on: July 11, 2009, 08:48:12 AM »
I think that the original 1176 has a lower threshold compared to the rev A.
As you can see, the preamp stage of the rev A has an higher feedback resistor.
If I'm not wrong that means less gain from the preamp stage then less signal in the sidechain.

The rev D ratio board is similar to the rev A. But different from the original 1176 (Mnats version)
In fact in the original 1176 the signal from the output pot goes straight to the meter board, when in the rev A or D there is a resistor in between.

That's why I think following the rev A schemo should help solve the problem.
But as far as I can see there is more stuff to change for a clone of a rev A.
Mako did a great work btw, but there is still something I don't understand.

Please Mako, chime in !
Neeno
Quote from: "CJ"
Hippies would never  kill a Llama. They might have dope crazed sex with it, but never kill it.
Quote from: "CJ"
REMEMBER, A FLUTE WITH NO HOLES, IS NOT A FLUTE, AND A DONUT WITH

orangerec

Re: Looking for: 1176 rev A schematic or high res internal shots.
« Reply #9 on: July 11, 2009, 11:59:59 PM »
Neeno, I replied to your email. Thanks for attempting a fix. I've been using my RevA for months and I love it. I don't use nuke mode much but if I need to, I use my G1176 or a Distressor.

Cheers,

Tony


Neeno

Re: Looking for: 1176 rev A schematic or high res internal shots.
« Reply #10 on: July 12, 2009, 06:51:24 AM »
Thank you for your reply Tony.

Now, as promised I post the comparison I did between the "Original 1176", "Rev A" and "Mnats Rev A"
Check out the attachment.

I still have to compare the ratio board resistor.
I'll do that and update the list later.
If anyone would like to check if all the values are ok, it would be just great.
« Last Edit: July 12, 2009, 07:16:28 AM by Neeno »
Neeno
Quote from: "CJ"
Hippies would never  kill a Llama. They might have dope crazed sex with it, but never kill it.
Quote from: "CJ"
REMEMBER, A FLUTE WITH NO HOLES, IS NOT A FLUTE, AND A DONUT WITH

Rob Flinn

Neeno,

Could you clarify exactly which diagram relates to which ?   

original diagram = the first diagram in manual which they only made about 125 of ??

Rev "A" value = 2nd diagram in manual serial numbers 125-216 ??

Is Mnats values from the diagram at Waltzing Bear ?
regards Rob

Capital letters.  The difference between helping your uncle Jack off his horse, & helping your uncle jack off his horse ........

Neeno

Hi Rob !
Well, the original 1176 is the first diagram in JBL pdf.
They did just 24. Serial from 101 to 125

The rev A is the second diagram "Titled Rev A" is what I call Rev A.

As you can see, the Blue Stripe diagram on Waltzingbear refers to the "original 1176" wich is not the "Rev A" and this is what Mako used (with some slight modifications).

Probably what we've built now is the first version of the 1176.

Hope it helps.
« Last Edit: July 12, 2009, 10:39:24 AM by Neeno »
Neeno
Quote from: "CJ"
Hippies would never  kill a Llama. They might have dope crazed sex with it, but never kill it.
Quote from: "CJ"
REMEMBER, A FLUTE WITH NO HOLES, IS NOT A FLUTE, AND A DONUT WITH

Rob Flinn

I've been comparing the diagrams & noticed that on the original R46 is 22k & on rev A it's 8k2,c ompared to Mnats 47k.   It strikes me that tese values would reduce the gain of the s/c amp significantly !
regards Rob

Capital letters.  The difference between helping your uncle Jack off his horse, & helping your uncle jack off his horse ........

zmix

INTERIOR SHOT OF MY 1968 Bluestripe 1176 #1
« Reply #14 on: July 12, 2009, 02:25:47 PM »
Here is an interior shot of my 1968 Bluestripe...
« Last Edit: July 12, 2009, 02:29:20 PM by zmix »

zmix

INTERIOR SHOT OF MY 1968 Bluestripe 1176 #2
« Reply #15 on: July 12, 2009, 02:26:51 PM »
And another... :)
« Last Edit: July 12, 2009, 02:29:33 PM by zmix »

Neeno

Chuck !
Thank you very very much for the pictures.
Is that a rev A ? Or is it the original version ?
Neeno
Quote from: "CJ"
Hippies would never  kill a Llama. They might have dope crazed sex with it, but never kill it.
Quote from: "CJ"
REMEMBER, A FLUTE WITH NO HOLES, IS NOT A FLUTE, AND A DONUT WITH

zmix

Chuck !
Thank you very very much for the pictures.
Is that a rev A ? Or is it the original version ?

Well, it is from 1968 or 1969 so it's as close to the original series as I have ever seen, plus it has the original all-black input and output knobs..!

Neeno

Thank you very much Chuck !
Do you have the original manual of the blue stripe ?
I'm looking for a schematic a bit more readable than the one supplied by the JBL manual.
Neeno
Quote from: "CJ"
Hippies would never  kill a Llama. They might have dope crazed sex with it, but never kill it.
Quote from: "CJ"
REMEMBER, A FLUTE WITH NO HOLES, IS NOT A FLUTE, AND A DONUT WITH

Rob Flinn

I've been comparing the diagrams & noticed that on the original R46 is 22k & on rev A it's 8k2,c ompared to Mnats 47k.   It strikes me that tese values would reduce the gain of the s/c amp significantly !

I just swapped out R46 for the 8k2 that is used in the REV A version.  It makes quite a difference to the operating range.   If using the 47k or 22K in the other versions it goes from nothing to -20db GR at about 10 o'clock input pots rotation.   With an 8K2 in this position -20db happens at about 12 o'clock on the input control.  The threshold point stays the same.

Basically it's more controllable.
regards Rob

Capital letters.  The difference between helping your uncle Jack off his horse, & helping your uncle jack off his horse ........