Identifying the OPamps in my EE Minimax Supreme

Dan Twomey · « **on:** 6 Jun 2016, 12:06 am »

Since I bought my MinMax Supreme with the LM49990's already installed there's not the usual identifying marks between the single and dual opamps. In the accompanying picture A and B at the back are marked U1 and U2 and C and D are marked U6 and U7. Can anyone tell me which are the duals and which are the singles?

Regards,
Dan

Wayne1 · « **Reply #1 on:** 6 Jun 2016, 12:37 am »

Sorry. Not really sure. Layout is different from first two generations.

The dual op-amps are used after the DAC chip as I/E stage.

The single op-amps are the solid state output that would go to the relay.

TJHUB · « **Reply #2 on:** 6 Jun 2016, 01:34 am »

In the past generation, U1 and U2 were the duals. You could just pop them out one at a time and look at them. The singles just have a chip on top of the board, and the duals have a chip on top and underneath the board. Just don't screw up the orientation of the opamps.

Dan Twomey · « **Reply #3 on:** 6 Jun 2016, 10:52 pm »

Thanks, I didn't know how to differentiate between the two types of LME49990's.

Regards,
Dan

Bill O'Connell · « **Reply #4 on:** 7 Jun 2016, 12:05 am »

When you look at the DAC from the front to the rear, the rear are the Duals ( A & B ), the fronts are the singles ( C & D ).

Dan Twomey · « **Reply #5 on:** 27 Jun 2016, 11:43 pm »

Quote from: TJHUB on 6 Jun 2016, 01:34 am

In the past generation, U1 and U2 were the duals. You could just pop them out one at a time and look at them. The singles just have a chip on top of the board, and the duals have a chip on top and underneath the board. Just don't screw up the orientation of the opamps.

TJ,

Many thanks for your advice. It led to a trouble free upgrade.

Regards,
Dan

TJHUB · « **Reply #6 on:** 27 Jun 2016, 11:58 pm »

Quote from: Dan Twomey on 27 Jun 2016, 11:43 pm

TJ,

Many thanks for your advice. It led to a trouble free upgrade.

Regards,
Dan

No problem. What opamps did you go with?

Rocket · « **Reply #7 on:** 28 Jun 2016, 12:50 am »

Hi Dan,

Do you have the minimax supreme? Which opamps did you upgrade to?

Cheers Rod

Dan Twomey · « **Reply #8 on:** 28 Jun 2016, 01:08 am »

Quote from: TJHUB on 27 Jun 2016, 11:58 pm

No problem. What opamps did you go with?

Went with the Burson V5's. First impressions are a very worthwhile upgrade. Detailed, smooth, and a great sound stage.

http://www.bursonaudio.com/products/supreme-sound-opamp-v5/

Regards,
Dan

Rocket · « **Reply #9 on:** 28 Jun 2016, 09:56 am »

Hi Dan,

I think this is a new opamp from Burson? Do they fit in the EE dac okay? I remember the older version were too tall for the Dac Plus. I opted for the Dexa's for this reason.

Glad you've had a positive result with the upgrade.

Cheers Rod

Armaegis · « **Reply #10 on:** 28 Jun 2016, 09:58 am »

The V5's are pretty new, and there's an even newer V5i which is even smaller.

Dan Twomey · « **Reply #11 on:** 28 Jun 2016, 01:45 pm »

Quote from: Rocket on 28 Jun 2016, 09:56 am

Hi Dan,

I think this is a new opamp from Burson? Do they fit in the EE dac okay? I remember the older version were too tall for the Dac Plus. I opted for the Dexa's for this reason.

Glad you've had a positive result with the upgrade.

Cheers Rod

The new v5 opamps fit into my DAC with no problems. The lid is back on!

Regards,
Dan

mrvco · « **Reply #12 on:** 29 Jun 2016, 03:59 am »

Good to know that the new Bursons fit. I wasn't crazy about the idea of leaving the DAC Supreme internals exposed.

I just installed the Sparkos Op Amps in mine. First impression after installation and ~1 hour of listening was very bright

I'm letting them burn in (24 hours and counting), so hopefully they'll settle down. The Bursons will be next on my list.

Bill O'Connell · « **Reply #13 on:** 29 Jun 2016, 08:48 pm »

Just a quick heads up.
We have had a few problems with the V5's in both the MiniMax Dac Plus and also the Supreme DAC. For some reason they seem to get noisy or just fail.
With that being said, they sound fantastic! Hoping they can work out the problem.
I haven't tried the V5i as of yet but I believe I will and have my fingers crossed that they sound the same or better.
The Sparko Labs op-amps sound wonderful also with no hiccups at all.

Armaegis · « **Reply #14 on:** 29 Jun 2016, 11:51 pm »

Quote from: Bill O'Connell on 29 Jun 2016, 08:48 pm

We have had a few problems with the V5's in both the MiniMax Dac Plus and also the Supreme DAC. For some reason they seem to get noisy or just fail.

Are they getting hot? maybe they're oscillating?

Rocket · « **Reply #15 on:** 30 Jun 2016, 11:08 am »

Hi Bill,

I have an Eastern Electric Minimax Dac Plus and have installed DEXA'S in the unit. Do you think it is worthwhile to swap these out for the
new Burson's subject to them being reliable?

Cheers Rod

TJHUB · « **Reply #16 on:** 1 Jul 2016, 01:42 am »

Quote from: Rocket on 30 Jun 2016, 11:08 am

Hi Bill,

I have an Eastern Electric Minimax Dac Plus and have installed DEXA'S in the unit. Do you think it is worthwhile to swap these out for the
new Burton's subject to them being reliable?

Cheers Rod

I have V3 Burson's (which some say are "better" than the newer ones) that I ran in my EE Plus for years. I now have Special Edition DEXA's. There are slight differences in the bass and treble presentation, but the midrange is VERY similar. A friend and I got together last year and compared his EE Plus with DEXA's to mine with the V3 Burson's. There was no winner. What would you change about your sound? I will comment more about the differences in sound after.

Rocket · « **Reply #17 on:** 1 Jul 2016, 11:30 am »

Hi,

I guess I am after the most transparent sound that I can obtain from my system that is all. Always looking to improve and upgrade. The EE dac plus with the DEXA's does sound very good.

Cheers Rod

TJHUB · « **Reply #18 on:** 1 Jul 2016, 11:48 am »

I forgot to finish my post...

In my system, the V3 Burson's have a slightly softer treble that also sounds more realistic. The DEXA's had a slightly more extended treble, but can present a little digital sound that takes away from the realism a bit. When not comparing them and just listening, it's not so apparent.

I find the midrange to be far more similar than different. The V3 Burson's have slightly more output in the upper bass/lower midrange area that gives them a richer tone, but the DEXA's present slightly more clarity and transparency in this range. Again, it's very close.

The V3 Burson's present a hardier bass than the DEXA's, but the DEXA's present as more defined.

I had the Sparkos at one time, but they ddidn'twork out at all. Very thin sound and lacked bass punch.

Overall, these DAC's really perform incredibly with either discrete OP amps. It would depend on the sound of your system as to which of these would sound best. I've tested many DAC's in my system, and none of them even come close to making me want to replace my EE Plus.

mrvco · « **Reply #19 on:** 1 Jul 2016, 06:29 pm »

Quote from: Bill O'Connell on 29 Jun 2016, 08:48 pm

Just a quick heads up.
We have had a few problems with the V5's in both the MiniMax Dac Plus and also the Supreme DAC. For some reason they seem to get noisy or just fail.
With that being said, they sound fantastic! Hoping they can work out the problem.
I haven't tried the V5i as of yet but I believe I will and have my fingers crossed that they sound the same or better.
The Sparko Labs op-amps sound wonderful also with no hiccups at all.

Bill - Thanks for the heads-up on the Bursons. Does it sound like an infant mortality issue or is it something that manifests itself over a period of time? I see that Burson offers both a 30-day refund and a Lifetime Warranty, I suppose I'd be covered either way.