Eastern Electric DAC mods

Wayne1 · « **Reply #420 on:** 25 Mar 2011, 05:38 pm »

The regulators for the op-amps are not the problem. They are easily upgraded and you are correct in that there are many options to choose from.

The biggest difficulty is in replacing the surface mounted regulators for the DAC chip. The Sabre chip is VERY sensitive to noise on the power supply lines. There are four regulators feeding it that can be replaced with the Hynes. To do so, there has to be quite a few component changes to allow the Hynes to work.

While it is quite a bit of small area work, it does yield some clearly audible improvements.

MarkM · « **Reply #421 on:** 25 Mar 2011, 07:19 pm »

Bravo to you for getting an upgaded regulator in that VERY limited spot.

I didn't realize you had been able to shoehorn something in there.

I have been staring at those suface mount 3.3v regulators for weeks

and have decided not even to take a stab at it.

Ah, if they had only used through hole mounted.....options would be endless for your customers.

Levi · « **Reply #422 on:** 25 Mar 2011, 07:54 pm »

I don't mind having a transformer sticking out of my EE Dac. ha ha ha!

Turnandcough · « **Reply #423 on:** 26 Mar 2011, 12:45 pm »

Quote from: MarkM on 25 Mar 2011, 05:29 pm

The Hynes regulators are tops on many lists for good reason, but with space being a real issue inside this dac, there are other choices that are a direct drop in for the LM317 & 337 with a few minor resitor changes. I installed the Belleson 2a regulators. Would have gone with my stand by Tentlabs regulators, but when I measured the current draw, (38ma-depending on op amps used) it exceeded the ratings of Guidos offerings.

Heat sinking is another issue as there isn't much room to add one that dissipates real energy. The stock heatsink allows for the small footprint wit a different regulator.

To get the most out of the opamps in this cool little dac, a clean low noise-low impedance regulator is key IMHO.

Another option perhaps for your customers?

After trying Super Teddy regs unsuccessfully on an $89 Chinese board I gave the Bellesons a try and was quite happy with the end result. If I had more DIY experience I would replace all the regs on the EE with them but I'm just to afraid to mess things up.
I was wondering if they could be a viable(cheaper) alternative to the PH regs.
I was also wondering about the use of opamps in the output circuit. While I'm quite happy with the sound a few "purists" I know have shyed away from the EE because of them.

Wayne1 · « **Reply #424 on:** 26 Mar 2011, 03:16 pm »

The Belleson regulators appear to be close to the same price as the Hynes. The Hynes are more compact. Paul is also very familiar with the working of the Sabre chip. He does have all the technical data on the chip and has signed the non-disclosure agreement with ESS.

The main cost is no so much the parts, but the R&D that went into figuring out how to mount the four regulators in an area where only surface mount parts are in the stock DAC. The labor to put them in is also rather high.

The EE DAC was built to a price point. I think it would be very hard to find too many DACs at that price point, with a true tube output, without op-amps. Most of the pro DACs all use op-amps. The fact that Alex did use op-amp sockets to allow rolling is a good thing, if you know what you are doing.

If you want a discrete I/V section, use a Buson or AudioGD discrete op-amp. You would have to keep the cover off. I do not think they will fit in the small amount of head room left in the case.

I don't think any one person's design of a DAC will suit everybody. The stock EE DAC DOES suit many people. With mods, it reaches out to more. If you throw enough money at it, it may even do everything anyone could want.

Levi · « **Reply #425 on:** 10 Apr 2011, 09:15 pm »

Hi Wayne,

I am about to order a Audio-GD EARTH OPA for the I/V section. It is a blind purchase because I am only going with their published specs: THD Less than 0.0005%(1KHz), Operating voltage：±9 TO ±25V，Open loop gain：35DB，Operating current： Approx. 28MA（Single OPA），Approx. 56MA（Dual OPA）.(Products have been upgraded to Cap Model, using EVOX MMK capacitors)...

They are slightly cheaper compared to the Burson Dual HD OPA. Hopefully it works with the EE DAC.

My first choice is the OPA-SUN : This discrete opamp uses full balanced circuit design which is widely appreciated by our Hong Kong and American followers among our other products. THD Less than 0.0003%(1KHz), Operating voltage ：±12 TO ±20V，Open loop gain：36DB，Operating current： Approx 25MA（Single OPA），Approx. 50MA（Dual OPA）.(Products have been upgraded to Cap Model, use EVOX MMK capacitors. )

My understanding is that EE DAC uses +-15Volts on the OPamp rail and max 200mA operating voltage. Hmmm...

Levi · « **Reply #426 on:** 12 Apr 2011, 01:39 am »

Here is another discrete OPA from DEXA. $85 bucks each.

Vsupp +/- 5V to +/-25V
Isupp less than 10 mA

http://www.partsconnexion.com/opamp_dexa.html

Cheers!

p.s. I am not taking responsibility if you decide to install these discrete OPA in your DAC. This is simply for our discussion purposes and not a suggestion. Do so at your own risk.

Turnandcough · « **Reply #427 on:** 12 Apr 2011, 09:01 pm »

A while back I tried the Audio-GD Sun and Earth and LM4562 opamps in a DIY DAC using a CS4398 chip. I remember the LM4562 ranking somewhere in between the two bested only marginally by the winner. In the end I ended up selling both GDs and opting for Jensen output transformers instead. Unfortunately I can't remember which one I preferred but as I mentioned the "improvement" was definitely not night and day. While the Dexas may be better I find the cost a bit steep considering you'll need two duals and two singles to do the job.
BTW - apparently Burson "borrowed" the design from GD and not the other way round.

Levi · « **Reply #428 on:** 12 Apr 2011, 10:56 pm »

I think the Dexas is the new kid on the block. I read lots of reviews about the Audio-GD and it appears to be a little cheaper.

Neogeo333 · « **Reply #429 on:** 21 May 2011, 07:03 am »

Latest news indicate that theres a MKII version slated for September release with better internals and most importantly 24/192 USB.

Big Red Machine · « **Reply #430 on:** 8 Jul 2011, 01:24 am »

Hats off to Wayne!! I received the modded EE dac today and after rebooting and rescanning and updating software I have the system running powered only by the "tiny" ATI 602 I have for sale.

I am mightily impressed. My memory does not recall such bass and detail as I have right now. Pavane tube and silver fuse of course.

The ATI is going through a Synergistic Powercell 4 and the PC's are a mix of my DIY and Triode.

Can't wait to get my Samsons tomorrow. Really impressive Wayne!!

Wayne1 · « **Reply #431 on:** 8 Jul 2011, 02:46 pm »

Thanks for the comments, Pete.

The DAC and power supply do have some hours on them. They will also improve over the next week.

I think you will continue to be happy with the sound of the modded unit for some time. In looking over the circuit board of the MKII Mini Max DAC, there does not seem to be much changed in the power supplies and analog output. Most of the changes seem to involve the input switching and USB section.

I would hazard a guess that the new DAC will not sound as good as any of the modded DACs I have worked on. It appears that some of the work I did on the first gen Mini-Max DAC can be carried over to the new one to improve the analog outputs and the power supplies.

I guess we will have to wait to find out until they arrive in country.

Big Red Machine · « **Reply #432 on:** 12 Jul 2011, 05:21 pm »

And BTW Wayne, the power supply you added the Bybee Rail to is considerably cooler than it ran before. I can hold my hand right on it and no heat issues and it has been on 24/7 since last Thursday. Whatever you did to remedy the situation seemed to do wonders. Now I need to try the new Touch still sitting in the box.

Levi · « **Reply #433 on:** 12 Jul 2011, 05:58 pm »

Are you sure they are not bybee filters? Ha ha ha!

Nevertheless, congrats!

Quote from: Big Red Machine on 12 Jul 2011, 05:21 pm

And BTW Wayne, the power supply you added the Bybee Rail to is considerably cooler than it ran before. I can hold my hand right on it and no heat issues and it has been on 24/7 since last Thursday. Whatever you did to remedy the situation seemed to do wonders. Now I need to try the new Touch still sitting in the box.

Wayne1 · « **Reply #434 on:** 14 Jul 2011, 12:23 am »

Preview of level 3 mod:

Coming soon

Gopher · « **Reply #435 on:** 14 Jul 2011, 12:29 am »

ohh really...

Without the space constraints, was there a lot more you could have done ECONOMICALLY with the minimax? With the upcoming Minimax DAC+ I'm wondering what you may have up your sleeve. Seems like it will baseline close to where the level 1 mods take the orignal... I'll be watching with interest.

Wayne1 · « **Reply #436 on:** 14 Jul 2011, 12:47 am »

Economically, no.

The new version DAC+ stock will NOT sound anywhere close to the older version with the level 1 mods.

The main thing Alex is doing is correcting the USB input and the switching circuit. The power supply is very similar. He is adding another transformer, but the current capacity of each circuit is the same. I do not see much difference in the tube circuit.

The case for the Level 3 unit can be ordered separately. Any first gen EE DAC can be fitted into the case.

Levi · « **Reply #437 on:** 14 Jul 2011, 12:57 am »

Looking at the pictures. I think Wayne is correct. That means, Wayne can make the EE DAC + even better.

Quote from: Wayne1 on 14 Jul 2011, 12:47 am

Economically, no.

The new version DAC+ stock will NOT sound anywhere close to the older version with the level 1 mods.

The main thing Alex is doing is correcting the USB input and the switching circuit. The power supply is very similar. He is adding another transformer, but the current capacity of each circuit is the same. I do not see much difference in the tube circuit.

The case for the Level 3 unit can be ordered separately. Any first gen EE DAC can be fitted into the case.

Gopher · « **Reply #438 on:** 14 Jul 2011, 01:23 am »

Quote from: Wayne1 on 14 Jul 2011, 12:47 am

The new version DAC+ stock will NOT sound anywhere close to the older version with the level 1 mods.

that was a point of concern for me, Wayne. Glad you addressed it head on!

That said, I'm wondering if it will be a more favorable platform for mods then the original or are we talking same difference.

Wayne1 · « **Reply #439 on:** 14 Jul 2011, 02:02 am »

From what I have seen of the unit so far, it appears to be pretty much the same thing as the first gen, for modding.

It will be "better" for people who wish to use USB and for multiple inputs. Sonically, it should be very close to the first gen. I do expect some improvement with the separate transformers, but nowhere near the sound of a modded first gen.

Right now this is all blue sky. I have talked to Bill at Morningstar and I will get a chance to audition the new DAC+ whenever it arrives in the country. I will be happy to post my impressions of it at that time.

The new case that Lou is building for the first gen DAC should be able to be adapted to fit the DAC+. Most of the level one and level 2 mods should carry over to the DAC+. I'm sure there will be some variations, but not too much.