ADL-1000 with Audio Upgrades optimization...smokin!!

[jho]

Hey just wanted to shout out to anyone that might be curious.

I recently sent an ADL-1000 to Jim Williams at Audio Upgrades, so that he could do a circuitry optimization and upgrade including Jensen transformers, and a bunch of other upgrades.

I have to say - this is one of my favorite tracking compressors ever now! It's absolutely transparent on vocals but adds a hi-fi clarity and warmth thing to it that's hard to describe! Also tried it on a mix with it on Bass... Unreal !! Completely transparent limiting with clarity and punch.

I'd have to say my little ADL with the relatively inexpensive upgrade really smokes a lot of compressors I have that cost 2X as much.

Highly recommended !

[DONNX]

cool deal, how much did it cost and what exactly did he do to it besides swapping out the custom transformers for jensens?

[jho]

Originally Posted by DONNX

cool deal, how much did it cost and what exactly did he do to it besides swapping out the custom transformers for jensens?

It was 400 bucks. He did the transformers, I think all the caps and films (?) and some tubes etc. Maybe he will chime in as to what exactly he did. I only paid 900 for my ADL to begin with so this is quite a cost-performer now!

[T.H.Reid]

My tech guy did the same mod for my ADL 1500, Jensen trannies and Wima caps, and new tubes (not NOS but all JAN's), based on Jims modifications. It is really an awesome beast now, especially tracking. Cheers, Thomas

[jho]

Originally Posted by T.H.Reid

My tech guy did the same mod for my ADL 1500, Jensen trannies and Wima caps, and new tubes (not NOS but all JAN's), based on Jims modifications. It is really an awesome beast now, especially tracking. Cheers, Thomas

Cool !! Have you tried the 1500 on a Buss ? I'd be curious how well it worked on a 2 mix (the right kind of song of course) or a drum buss or something at mix time.

[T.H.Reid]

Actually, the other day I tried it on a fairly sparce rootsy reggae song with no GR just for size (letting a 5043 do the work), and it was amazing! Large! The artist was stoked!

[jho]

Originally Posted by T.H.Reid

Actually, the other day I tried it on a fairly sparce rootsy reggae song with no GR just for size (letting a 5043 do the work), and it was amazing! Large! The artist was stoked!

Very cool !

[TonyR]

That sounds very cool!

Does anybody know where I can get such an audio upgrade in Europe / Germany?
I have an ADL 1500.

Thanks!

Antoine

[DONNX]

I was thinking about getting a pair and putting the old UTC trannies from the old LA 2A in these. Has anyone else done this yet?


I got the trannies. Just need some more info. Wilma caps made a big difference?


Thanks guys.

[tylerp]

I did this mod for someone. The UTC's maybe added a little warmth but the main problem with the ADL1000 is just a small design issue. I actually don't have a problem with ADL transformers... unless its that they are too clean!! I understand DeMaria transformers are custom made just for his product. I measure a higher, winder band pass then the UTC's do with a bit less distortion. He probably had to get them made custom to obtain the right impedance match with the LA-2A circuit design. I measure 15hz-25Khz through them with very low distortion. The UTC's I had rolled off at 15Khz. I'm happy with my ADL1500. I wouldn't change it except possibly to add a variable knee adjuster.

[Jim Williams]

I use MIT MultiCaps, not WIMA for the signal path. I also used some silver foil, paper in oil caps for an ADL that went to Martinique, those are sweet. Several resistors are changed to Dale. The output cap is 105 degree Nichicon at 22 uf. Another MIT is used across it. I also install large 220 uf mains caps, 105 degree rated. Rectifiers are fast recovery. Wima's are used for psu bypass.

The Jensen output transformer is -3 db at 60k hz. It's like after your ears pop landing in a jet next to those 15k hz UTC's. The ADL transformers are very mushy. I send them back and recommend customers mount them in a box with XLR I/O's for "colors" and slop.

I've also added the Jensens and MIT's to LA-2A's, those also really open up nicely.
They require some large mains caps to remove residual hum leakage.

Jim Williams
Audio Upgrades

[Jimbo]

Originally Posted by tylerp

I did this mod for someone. The UTC's maybe added a little warmth but the main problem with the ADL1000 is just a small design issue. I actually don't have a problem with ADL transformers... unless its that they are too clean!! I understand DeMaria transformers are custom made just for his product. I measure a higher, winder band pass then the UTC's do with a bit less distortion. He probably had to get them made custom to obtain the right impedance match with the LA-2A circuit design. I measure 15hz-25Khz through them with very low distortion. The UTC's I had rolled off at 15Khz. I'm happy with my ADL1500. I wouldn't change it except possibly to add a variable knee adjuster.

TylerP: You've mentioned mods to the ADL1000 in recent posts. I've also found someone on eBay that offers to modify the gain control element of the ADL1000 so that it behaves like the LA2A.

Do you (or anyone else) know anything about this mod?

Thanks.

[tylerp]

The ADL1000 has an issue IMO that I can only attribute to board layout. Correcting that one issue causes a bigger change in that box than anything else I can think of one might want to do with components. In the ADL1000 there is, IMO, a gain reduction eq issue that's designed in perhaps not by intention. I don't know. I detailed it to Anthony once. No feedback. Notice: I'm being careful with the wording here because of board posting policy. The ADL1500 which uses a different circuit board does not have the issue and works as I would expect out the box.

Regarding the UTC's As I said, measurements show the ADL transformers outperform them but they may just be cleaner than some would like. I use Jensens in some of my gear. They are excellent too. Quality components can certainly improve things but the gain reduction issue I'm talking about in the 1000 model is major.

[tylerp]

Originally Posted by Jimbo

TylerP: You've mentioned mods to the ADL1000 in recent posts. I've also found someone on eBay that offers to modify the gain control element of the ADL1000 so that it behaves like the LA2A.

Do you (or anyone else) know anything about this mod?

Thanks.

You may have seen a posting I have there. I do correct this issue for people in addition to work I do for my own studio.

[Jim Williams]

Originally Posted by tylerp

You may have seen a posting I have there. I do correct this issue for people in addition to work I do for my own studio.

In the public interest I showed mine, will you show yours?

Jim Williams
Audio Upgrades

[tylerp]

Ha ha. Well it took me several days of painful board foil tracing, singnal injecting and scope work to find it so I like to hang on to that one. However I have dropped some --very loud hints.-- Its in the area of gain reduction Eq and its a board layout issue that the 1500 doesn't have. That narrows it down to a handful of components. Since you are obviously as far into LA-2A design as I am I bet you can find it if you haven't already.

I also do some other things that take exception to what Anthony does to get a bit more gain reduction. One of then has to do with R24. Its a 2 W resistor in the middle of the board that gets rather hot. On some ADL's its 10K. On LA-2A its 22K. Thing is at 22K the waveform going into the GR element gets flat topped on one side as the plate current is insufficient. This affects attack and knee a little bit. Drop the plate resistor to 10K and you get a good wave form but some of the output is lost in the power supply because the plate resistor is less than the load impedance of the GR element. So I strike a balance and set it for 15K at 4 watts (using 2 30K 2W) to keep the temperature down and squeeze a few extra db GR out.

So there. Gave you something back. You will also see other minor differences between the La-2A and DeMaria in various places all over. For example R7 is way different. That affects the knee. The list goes on and on. Most of the differences are OK and I understand them. Some I change. To find this stuff its helpful to strictly compare the LA-2A schem. with ADL1000 component by component and analyze each difference.

[tylerp]

Also. The schematic I used was not this one but I've spot checked it and the component numbers appear to be all the same as the one I use. In fact I like this one better. You can find all the issues by doing a careful comparison.
The Free Information Society - Urei LA2A Electronic Circuit Schematic

[tylerp]

I thought it might help top post some pictures that show the ADL1000 GR problem I've encountered. When you look at each of these you see an envelope on the screen. The top of the envelope is the response curve with frequency going up from left to right and amplitude vertical.


Unmodified with no gain reduction Sweep 50-100khz



Unmodified ADL1000 with gain reduction
applied upward response slope is very apparent.



ADL1000 with heavy gain reduction after correction.
Response is flat under reduction and there is more of it.

[Apollo Soul]

giving some serious consideration to picking up a used unit and having it modded. I love classic LA2A, but when it's my money, I refuse to go antiquing.

Mainly interested in replacing a few parts (caps, transformers, etc...), but would like to know a bit more too if anyone can chime in about any other mods (ebay stuff, for example)

[tylerp]

The main audio chain in the LA2A and the ADL1000 is almost direct coupled. The real difference between the two is they are not identical in circuitry and those differences though small have a dramatic effect on performance. The differences can be modded out and then both sound very similar. That's what I do. Its not the components used that make them perform differently as stock. Its the electronic design differences.