Should I be disappointed with SSL?(alphalink AX)

[Svart]

ok the box came in today, they had it done and sent back out within a couple of hours.

I need to get some time to open it back up and see what was done..

 

[Svart]

A quick look inside:

looks like the digital board might be different. it'll be this weekend before I can really get into it and check it out.

 

[Svart]

ok some tracing done..

all seems well in analog land except for the output..

imagine this, 4 channels use 12 coupling capacitors..

HOW? you ask..

Because the -output is impedence balanced, not true balanced.. it goes from connector to a ferrite to 120R straight to ground..

everything else is datasheet copy.

the digital board was replaced, I'm pretty sure of it.

The board now has a nice FPGA, a cpld, some memory, some proms and other assorted stuff. Seems that the clock is derived from the FPGA itself but there is a discrete PLL clock setup on the board that leads directly to I/O pins on the FPGA. I suppose the FPGA does the conversion for the various timings.

The voltage rails are derived from a SMPS on the analog board itself.. this part actually looks rather good. I bet the rails are nice and stable at least.

More on this later.

 

[Moby]

Cool, so do you have some listening impressions? I had a chance to listen the upgraded "thing" once, but not in my environment. I compared to the Ap*gee ad da 16 and seems that SSl sounds pretty musical... Also, I was confused about bunch of elco's inside. :?

 

[Svart]

It sounds just fine. It's a quality sound and the build quality is good but there are portions of the design that I find "cheap" like impedence balancing the outputs instead of fully balancing and using the 'lytic caps instead of servos and other things I expected of SSL.

However don't be fooled by my complaints, the unit sounds good!

I bit the bullet and changed the opamps on 2 channels with lm6172 and there is a change in sound. it has a slight bit more highend but rather not worth the time and expense to change the parts out. I bypassed the output caps on those channels with jumpers and didn't hear much of a difference. I'll try the inputs next. I'm NOT taking the caps off the board. I tried to do one but the traces are SOOOOOOO damn small that the pad started to move so I quit trying and just jumpered it.

This board is NOT modification friendly. I have a special SOIC removal tip for my metcal which allowed me to get the opamps off the board but I don't see getting them off by regular means at all, it's just too damn tight of a fit with the local components which are all 0603 SMD parts.

 

[Moby]

Great. My listening impression was similar. I'm glad to hear that you don't hear any sound change with bypassing caps. Must be that topology is based on the old SSl audio path. Series 4000 and 6000 is filled with elcos and still sounds great :wink:

 

[Svart]

yes those are filled with caps but most of those caps are back-to-back bipolar approximations and are DC biased. these are just polar 'lytics in the signal path.

 

[Svart]

I did more testing while straight bypassing the input caps as well..

I actually liked it better with the caps in the path, the straight wire sound was a little on the raspy side. Maybe I'll try bypassing with a film and see if it makes any difference but I don't think it will.

So far I like the unit with the lm6172s for high end clarity but the NJM IC seems to sound just fine.

It's got some thump in the low end too, but not too boomy like the tascam was.

The box seems cheap but the sound is good.

I'm suprised Wayne hasn't chimed in lately!

 

[pan]

Can you tell me, what the unit is calibrated at?

-18 dBFS at +4 dBu ?

 

[booboo12]

I know it's been a long time...

People over Gearslutz have reported problems with analog I/O. When some have escaped with bad ribbon cable connection some weren't so lucky. Unfortunately same happened to me and it is NOT the ribbon cable. I've tried SSL e-mail support with one answer per day frequency with no luck. Same $714.05+ shipping "solution" cause their techs charge £96.60/hour!! (Wish I could get job there).
Next I suggested them to arrange a telephone call for me with their tech that has the schematics @ £96.60/hour so he could help me troubleshoot the unit.
SSL answered: "Unfortunately this is an unusual fault and we cannot narrow it down to a small enough set of components that you could replace. It's a complex problem that could need a lot of time to check and additionally, schematics would be needed for any repair and as a matter of policy SSL does not share those." Yea, yea at least 2 people with ribbons and other 2 with dead analog boards. I'm so pissed! I've got those converters second hand and was very happy how they sound but not for too long.

Anyway I've done some troubleshooting and discovered there's no power to Opamps +/- rails so the fault is in onboard part of DC/DC conversion...

One thing they're right - you need schematics.

Anybody has something to share on this one?