SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011

[fonkytone]

hi guys

i take a lundahl 1538 on PCB, what's is the R and C on R8,R16,C11,C18?

do you have any Idea?

thanks for your help

best regard

 

[culteousness1]

Look for "LL1538 Zobel" with the search engine of your choice.
This might help at least for some of the stated components.

Best,
Carsten

 

[fonkytone]

ok thank you for this information
i check the zobel network, but is not simple

i have another question, do you know if the jensen JT 115 k EPC work fine with the footprint

thanks

best
anthony

 

[bruno2000]

ok thank you for this information
i check the zobel network, but is not simple

i have another question, do you know if the jensen JT 115 k EPC work fine with the footprint

thanks

best
anthony

The 115 will not fit, but the 110 will.
Best,
Bruno2000

 

[fonkytone]

thank you for your reply and thank you for this wonderful project

best anthony

 

[CemD]

I also bought a PCB 9K5.
Thanks for bruno2000 design. He's just awesome.
Gustav thanks for the very high quality PCB.

I started to assemble. But a few questions (to start).

Can R1, R2 (10R Fused) replace power at 0,25 W 10R Fused. Or replaced by simple resistors MF 10R.
Where can I find the file front panel SSL9K5. Who will help me. I'm interested in CorelDRAW and PDF.

I hope for your help.

Thank you.

 

[bruno2000]

I also bought a PCB 9K5.
Thanks for bruno2000 design. He's just awesome.
Gustav thanks for the very high quality PCB.

I started to assemble. But a few questions (to start).

Can R1, R2 (10R Fused) replace power at 0,25 W 10R Fused. Or replaced by simple resistors MF 10R.
Where can I find the file front panel SSL9K5. Who will help me. I'm interested in CorelDRAW and PDF.

I hope for your help.

Thank you.

You can use just about any 10r 1/4 W resistors. 
I can send you a Front Panel Designer file of the front panel if you'd like.  PM your email.
Best,
Bruno2000

 

[CemD]

Thanks for your help and support topic.
I sent PM.

 

[Kimster]

Hi!

Just built the 9K and it works just fine, but I´m having problems with scratchy gain pots. Did I just have some bad luck with the pots or is it something else?  ??? Otherwise everything works fine, but I haven´t installed the meter bridge yet - waiting for parts.

 

[Kimster]

Just found out that some of the resistors needs matching. I´ll try that! 

 

[Kimster]

Ok, matched the resistors and it´s definitely better, but there is still som crackling when on high gain settings. Wonder if it´s a bad batch of Mat-02 I had or does anyone have another guess? It´s not a big problem cause I seldom move the gain during recording, but it would be nice to get rid of the crackling anyway! 

 

[SubhumanRecords]

Greetings, I no Brunno2K is out on a remote gig, I'm sure he will get back to ASAP. He will no what's ups.

M....

 

[fishdrop]

Hey Guys,

I read the whole thread carefully and prepare my part shopping.

is there any fpd file for the 4k5???
i opened the 9k5 files, but for any reason i cannot change the labels.
also i don't know if the front panel layout is the same.

would be nice to get some advice.


all the best

 

[culteousness1]

The frontpanel file fits both preamps. The only problem is the gain label that varies between both amps.
Bruno's file contains a non-editable HPGL as engraving. You can either delete it and roll your own labels
or design a new HPGL using the graphics software of choice. I took the second option...

Best,
Carsten

 

[fishdrop]

The frontpanel file fits both preamps

The only problem is the gain label that varies between both amps.

OK. i understand.
i'd like to use the Jensen JT 110 Transformer. thought about using JT 115, but the PCB doesn't take it. 
what would be the correct gainlabel??

Bruno's file contains a non-editable HPGL as engraving. You can either delete it and roll your own labels
or design a new HPGL using the graphics software of choice. I took the second option...

OK. Is it possible to export the HPGL to a file and modify it in Gimp or Photo Shop??
I'm sure i can do it when i play around a little bit.

 

[culteousness1]

i'd like to use the Jensen JT 110 Transformer. thought about using JT 115, but the PCB doesn't take it. 
what would be the correct gainlabel??

Dunno. Would suggest to go through the thread again. Easiest way:
Use the Print Page and the search function of your web browser (Crtl+F)  8)

OK. Is it possible to export the HPGL to a file and modify it in Gimp or Photo Shop??

Again, can't really help here. Maybe Google or some fellow DIYer...

Cheers,
Carsten

 

[bruce0]

i'd like to use the Jensen JT 110 Transformer. thought about using JT 115, but the PCB doesn't take it. 
what would be the correct gainlabel??

Dunno. Would suggest to go through the thread again. Easiest way:
Use the Print Page and the search function of your web browser (Crtl+F)  8)

OK. Is it possible to export the HPGL to a file and modify it in Gimp or Photo Shop??

Again, can't really help here. Maybe Google or some fellow DIYer...

Cheers,
Carsten

Suggest a look at JensenTransformers.com they have clearly stated a calculation to calculate ideal source impedance (which along with mic impedance to give you reflected secondary (source for the opamp) impedance gives you transformer selection).  Easy math and informative.  You can find it on the site at the bottom of the input transformer list and is expressed in 2 or 3 lines of text.

Not sure if I did it right, but here is what I got for various opamps.  It is all based upon Voltage Noise and Current Noise specs.

Of course many old designs were not ideal, or used non-ideal parts, so if you are replicating the job is archeology not math.

 

[fishdrop]

i could solve my frontpanel problem.
a nice diyer shared his fpd file with me. everything in this file can be changed.
if somebody wants it, pm me.

Suggest a look at JensenTransformers.com they have clearly stated a calculation to calculate ideal source impedance (which along with mic impedance to give you reflected secondary (source for the opamp) impedance gives you transformer selection).  Easy math and informative.  You can find it on the site at the bottom of the input transformer list and is expressed in 2 or 3 lines of text.

Not sure if I did it right, but here is what I got for various opamps.  It is all based upon Voltage Noise and Current Noise specs.

Of course many old designs were not ideal, or used non-ideal parts, so if you are replicating the job is archeology not math.

JT110 looks like a good choice


does anybody know the correct values for the zobel network when i use the JT110??
i'm a newbie
jensen's datasheetsheet, does not specifically contain the zobel network's parameters.
my conclusion from their test circuits in the datasheet is R8=100k, R16=30k1, C11&C18=56p?? or 100p??

would be nice if a experienced diyer could enlighten my darkness and verify my values or correct me if i am wrong.

all the best

transformer's datasheet:
http://jensentransformers.com/datashts/110khpc.pdf

 

[bruce0]

Using Jensen's calculation your choice seems right to me.

Re: Zobel

I think page one of the datasheet does specify a zobel for a typical application.  And as you say it is 100K load in parallel with (56p in series with 30k1).

So in the 4K schematic: R8 100K, C11 56p (npo or c0g) and C18 open (do not populate)

I should point out though, that while I think jensen's calculation would have you choose the 110, that my copy of bruno's 4K schematic specified the Jensen 115EPC as a choice (this might have changed), which is a slightly higher ratio (1:10 vs 1:8) and uses no zobel and a lighter load on the secondary.

 

[fishdrop]

Hey Bruce0. Thanks. i really appreciate your help.

I should point out though, that while I think jensen's calculation would have you choose the 110, that my copy of bruno's 4K schematic specified the Jensen 115EPC as a choice (this might have changed), which is a slightly higher ratio (1:10 vs 1:8) and uses no zobel and a lighter load on the secondary.

right now im torturing myself if i should go for JT110 (good match to the op amp) or if i should use the JT115 (like in the original SSL 4000 channels)

does an original SSL Channel use a different OP amp? or is it the same? i wonder if there is a big sound difference between those two trannies.

Bruce0: How do you like your Pre with the JT115 soundwise / musically??

i know that the PCB douesn't take the JT115, but on gustav's pcb there are holes where i could build a mount for a cabled version of a trannie. Do you have a picture of your JT115 mount??


all the best