SSL clone: enhanced input & output section

[Purusha]

Yeah, what happend with this Jenesen mod at the end?

What is the verdict?

 

[SSLtech]

[quote author="matthias"]1) why is there still the need for the 5532 after the vca??[/quote]
Because the VCA is current output.

[quote author="matthias"]2) is it not possible to connect the vca output directly to the drv134 input ??[/quote]
No. See my answer to 1

[quote author="matthias"]3) why are there 100r resistors at the output pins of the drv134 ??[/quote]
Presumably to limit current. -I do it (often using 47R or similar) because of the benefits in terms of not blowing up ICs when they see a short. DRVs are apparently less prone to this than the SSM version (SSM2142) but it happens. It's a good plan, though replacing them with links is ab option. -Want to know if there's a sonic difference? -Try it with & without then decide for yourself... -how much does a resistor cost?

[quote author="matthias"]4) are the "47k to ground" resistors after the coupling caps still needed??[/quote]They are an excellent idea. They help discharge the output plate to ground so you don't store a charge and get a "bang" on re-connection, they also help drain phantom down from 48V if you accidentally connect them to a live mic input.

I basically do all of this in my OB-1 ("Obi-Wan") boards that are the output balancing drivers for the DIY SSL 9K preamps.

Keith

 

[Purusha]

Sounds nice. Any chance to hear some sound proof? :grin:

 

[matthias]

thanks to keith for pointing that out !!


the actual circuit with the drv134 line driver at the output would look like this:

as you can see, the drv134 already contains a 10k resistor to ground and a 50R resistor in series with the output pins for current limiting..


so I would say I just need some coupling caps and that's it....


???


mat

 

[radiance]

[quote author="RogerFoote"][quote author="Purusha"]Yeah, what happend with this Jenesen mod at the end?

What is the verdict?[/quote]

I did a pair with JT-11 's on the input and outputs. They sound amazingly smooth and quiet. You can hear most difference with input iron because (I assume) of error in the electronically balanced inputs. Not knocking the input structure, but there is a silkiness and less grainy quality with input iron. The output iron kicks ass too, making the unit even quieter because of better matching between the GSSL and the next stage.[/quote]

Hey Roger, How exactly did you wire the output iron?

Thanks!

 

[radiance]

Thanks Roger :thumb:

 

[Rigpa]

Does anybody have the schematics for the Jensen output with iron? I dont quite get the description.

 

[jensenmann]

first page, first picture of the thread. Or do you mean something else?