Kevin

Hi Friends
Since the last weeks i'm designing this loved SSL Styled Preamps for 500/51X series
my shematics base on the E149, E01 ,G291 and 9k which are in the docs for the preamp section
In my Version I added a lot of other extras and frequency selective Low Cut and High Cut Filters.



Features
Gain - 16-68 dB  Gain Stepped easy recallable with Grayhill Switch (9K-J)
Gain - 26-68 dB  Gain Stepped easy recallable with Grayhill Switch (4K-E01 + 4K-G91 + 4K-E49)
48V - For Phantom Power Microphones
Pol - Switches the Polarity of the Input
Pad - Enables - 20dB Pad at the Input
Low-Cut filter - 10-250 Hz (24dB/oct)
High-Cut filter - 3.5-20 kHz (24dB/oct)
Colour Module (DIYRE) - to add coloration
Output Fader -  -∞ to +12dB after Preamp
Level Meter - internal switchable After Fader or After Preamp
Peak Led - After Preamp
SL9K-J + SL4K-G91 + SL4K-E49 are equipped with AS194H Super Matched Transistors
SL4K-E01 is equipped with Jensen JT-115K-EPC

More Details:







Avaivable Colour Module from Link Audio:

Colour Module Combines The Mojo Maestro and a Fet Saturation
Fet Saturation can be bypassed via Jumper
Sym and Asym Diode Clipping via Jumper
Diode Clip - Hard , Med, Soft via Jumper
Low Gain/ Normal Gain via Jumper
IC is a NE5534 or a DOA can be socketed

Here are some listening samles for the Preamps
https://soundcloud.com/linkaudiodesign/sets/sl-preamp-comparison-test-1

you also can shop via
https://linkaudiodesign.bigcartel.com
all shipping info for worldwide shipping can found there also

All Build Info(BOM,Schematic/Overlay/Stepbuild) will be avaivable under this link
Soon here;)

White Market Thread
https://groupdiy.com/index.php?topic=76303.0


NOTE: For all who assemble the Preamp on theirself this not a beginner project, i would say it's a bit more complicated than an VP312 but not that difficult than a BT50. there is just one simple calibration step after the building. But if you did this before you should be able to get this Preamps together.
« Last Edit: March 01, 2021, 07:05:26 AM by Kevin »


Whoops

Re: 500/51X Series \ SL9K-J + SL4K-E + SL4K-G \ SSL styled Preamps
« Reply #1 on: February 23, 2021, 11:03:53 PM »
To clarify a bit I use

SSL 82E149 transformerless thats formerly also a E Series but with two LM394, The G series is a bit similiar from that circuit design.

SSL 82E01 Transformer based with JT115K-EPC like the original used on the cards

Hello Kevin,

The G series circuit is the T82291 or SSL 82E291, I posted 2 schematics of that circuit in the technical docs section, here:

https://groupdiy.com/index.php?topic=45604.0

So you said you used the 82E149 circuit, then it's not a G series , that's an E-Series trasformerless circuit.
So you did 2 different E-Series circuits but no G-series circuit at all, or am I'm missing something?

Thank you

Whoops

Re: 500/51X Series \ SL9K-J + SL4K-E + SL4K-G \ SSL styled Preamps
« Reply #2 on: February 23, 2021, 11:20:40 PM »
Info on the SSL 4K consoles Different Preamps:


E SERIES

E-series are 82E01 or 82E149
The original was card number 82E01 which used a Jensen transformer.
Later on came the 82E149, which was the first of the transformerless designs.

The 'E' preamps used a pot with a push/pull switch to engage phantom, and a 20dB pad switch, below the red polarity button. they were available as transformer (Jensen JE-115K-E) on the 82E01 board, or with an LM394 matched-pair transformerless input on the later 82E149 version.



G SERIES

G series preamp with a dual LM394 front end, and a switched gain
The G series was the 82E249 and had a step-switched gain control, instead of the dual-gang pot

The first 'G' series input card was different in that it used a stepped attenuator/switched gain instead of a variable gain control, and no push/pull for phantom, so the pad switch was sacrificed, and the range of the preamp extended downwards.  The G-series used a solid-state differential front end with a matched pair of parallel transistors for low noise .

Kevin

Re: 500/51X Series \ SL9K-J + SL4K-E + SL4K-G \ SSL styled Preamps
« Reply #3 on: February 24, 2021, 01:23:06 AM »
The G series circuit is the T82291 or SSL 82E291, I posted 2 schematics of that circuit in the technical docs section, here:
https://groupdiy.com/index.php?topic=45604.0
So you said you used the 82E149 circuit, then it's not a G series , that's an E-Series trasformerless circuit.
So you did 2 different E-Series circuits but no G-series circuit at all, or am I'm missing something?
The Main Reason i named my Preamp a G is the difference that my G has also Stepped mic gain switch. also it uses the same 500 Ohms for the Gain. And in the shematic its called E4 Version. So not totally everything clear by the way.

and the original G Series uses just three opamps to make sound. Check the shematics of SSL 9K and 4K 292.71.4 they more added something like a next stage to it. So the the E149 is more an old school preamp - indeed if you say there two E-Series yes i have designed two E Series.

I still can do the G-Series, but i see some problems in the shematic, cause I don't find the point where the second deck get connected. Since it's a dual deck for Gain one 10K+500R and that need to be connected somewhere to make sound. otherwise its just the 500R for making gain. If you help to highlight that i could be quick and do the 4th preamp and do another design and will also offer this ;) If this is wanted?

And yes in my opinion I already did now an half G Preamp since its stepped.

Whoops

Re: 500/51X Series \ SL9K-J + SL4K-E + SL4K-G \ SSL styled Preamps
« Reply #4 on: February 24, 2021, 04:49:50 AM »
I still can do the G-Series, but i see some problems in the shematic, cause I don't find the point where the second deck get connected. Since it's a dual deck for Gain one 10K+500R and that need to be connected somewhere to make sound. otherwise its just the 500R for making gain. If you help to highlight that i could be quick and do the 4th preamp and do another design and will also offer this ;) If this is wanted?

I think it would be great to have the G series preamp, it was still not done in this forum.
I would buy a couple myself, other people would have interest also.

I can help you out filling the missing information, I will PM you so I can share more docs with you

Thank you so much
« Last Edit: February 24, 2021, 10:31:57 PM by Whoops »

Kevin

ok I've included the G291 Preamp in my designs. No real photos yet, but yes we will have 4 different Preamps!
i will actualize my shop also for this!


signalflow

Re: 500/51X Series \ SL9K-J + SL4K-E + SL4K-G \ SSL styled Preamps
« Reply #6 on: February 25, 2021, 12:06:18 PM »
I still can do the G-Series, but i see some problems in the shematic, cause I don't find the point where the second deck get connected.

Is that second deck of the gain switch not used for total recall? I don't think this circuit requires a dual deck for gain. I haven't studied the computer side of it so I can't be 100% certain but as it looks in the schematic I don't see a reason or the connections for it. 

-Casey
The shortest distance between two places is a nap.

Kevin

Yes of course. You can use a single deck also. I keep that in my design since i have other preamps with dual decks. Last time i ordered more dual decks than single decks an can also use a dual if I have no single available. That makes it possible to use alternatives when grayhill is sold out again ;)


 

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