Eastern Electric DAC mods

Gopher · « **Reply #180 on:** 30 Dec 2010, 04:28 pm »

I spent a few hours with the modified DAC last night and my first impressions are pretty darn favorable. I could tell right off the bat it was an appreciable upgrade to the stocker in terms of clarity while being weightier/more harmonically developed while having a bolder, more vivid quality.

It wasn't quite gelling with the interconnects I used on my stock dac with Siemens Silverplate tube, but after an epiphany, I tried another IC and it balanced things our really well--I ended up listening into the late night.

I'll post some more detailed thoughts as I continue to listen, but my first night with it was quite enjoyable.

Levi · « **Reply #181 on:** 30 Dec 2010, 04:50 pm »

Nice first impressions Gopher. Can you please concentrate on the leading edge/attack compared to the stock DAC? Led Zeppelin CD...something fast with lots of instruments please.

Thanks.

Big Red Machine · « **Reply #182 on:** 30 Dec 2010, 05:42 pm »

Wayne, is the vol control bypassed in the mod unit? I'm using my stock unit direct to the amp right now as I am w/o a pre and it is working fine with plenty of gain. Not gonna preclude a preamp but decent. Anyways, could be on the tour if the vol works.

Wayne1 · « **Reply #183 on:** 30 Dec 2010, 05:52 pm »

I left the volume control and selector switch alone in the tour unit.

Both Bill's units had the volume control bypassed. Bill@Lake George also had the selector switch bypassed.

srb · « **Reply #184 on:** 30 Dec 2010, 06:04 pm »

Quote from: Wayne1 on 30 Dec 2010, 05:52 pm

Bill@LakeGeorge also had the selector switch bypassed.

Is an actual digital audio signal being routed through the selector switch or is it merely an extension of input enable pins at the chip?

Steve

Wayne1 · « **Reply #185 on:** 30 Dec 2010, 06:09 pm »

The digital signal is being switched with the mechanical switch.

With the small size of the case being used, there is no room to add a different switching system.

Downsize · « **Reply #186 on:** 30 Dec 2010, 09:30 pm »

Sound quality report

I have been doing some close comparison work with the EE DAC being fed straight from my laptop via it's USB input, and with the DAC being fed Laptop > Off Ramp 3 Superclock 4 > AES/EBU input.

There is an easily heard improvement when going through the Off Ramp first. Now wether this is due to the Off Ramp, or due to the USB input being inferior to the other inputs I do not know. But the differences are more detail, better separation, slighty better texture and a MUCH airier and larger soundstage.

What is really interesting, is this is with using a completely unbroken in digital cable. I will be finishing my own custom cable using a silver/gold alloy soon, and that should REALLY make a difference.

Interesting stuff as far as I am concerned.

Gopher · « **Reply #187 on:** 31 Dec 2010, 03:00 am »

Alright, so this sucker was on all day while I was in the office and when I got in, fired up the rest of my rig and actually sat down to listen my jaw dropped. This thing had a good first impression on me, but things are just sounding really damn good today.

Levi, leading edge/attacks are damn good and excitement is there in full force, but I need to A/B to really get a feel there as the stock dac is not a slouch in that department. Today what I'm hearing is depth, definition wonderful staging and an uber natural tone. Liquid, bold and beautiful--this thing really jumps up a notch.

Wayne,

I can tell this modded DAC is driving the tubes far harder then the stock dac--when I was going to roll them before the 12au7 was actually hot and I had to hold off longer than with my stock... What does this mean for tube life? The Pavanes aren't cost prohibitive, but they certainly aren't cheap--nor are the other nice NOS choices.

Also, does the tube toggle actually STOP the tube from being powered/killing its life when idle with your mods?

Yowser--this thing warmed up/stablized really is damn good... I liked it yesterday, but today I'm fearing for my coin purse.

Edit: I should also note this bass hits harder.

Wayne1 · « **Reply #188 on:** 31 Dec 2010, 03:20 am »

Fred,

I can't really say how long a tube will last. It isn't being run all THAT hard. The stock circuit runs the plate current at about 4-5 mA. I'm running it at 9.5 mA. A 12AU7 is rated to 25 mA.

So in non tech talk, in stock form the tube is kinda loafing around. I'm making it work a bit harder, but less than half of what it's max effort could be.

The switch on the front is just for a relay to change between the op-amp outputs and the tube output. The power is on to all the sections at all times the power button is on..

You description of liquid, bold and beautiful is just what I heard on my system. Great stage depth and width with a very quiet background. Running the Paul Hynes regulators on top of what has been done to the touring DAC just turns all that up, for a very high price.

Turnandcough · « **Reply #189 on:** 31 Dec 2010, 05:33 am »

I just started listening to my stock DAC at low volume about an hour ago and I'm very pleased with my first impressions. I'm using a Genalex Gold Lion and an Hi-Fi tuning 800ma fuse. I'm a bit impatient and those were readily available locally. I'm going to borrow a few tubes NOS over the weekend and see what transpires. I might give the Pavane a try too but for now it's sounding pretty good as is.

I'll most definitely be considering the mods sometime in the near future but the holidays have made quite a dent in my budget so I'll need to recuperate first. Also, at this point, the thought of being without the EE DAC for any length of time is not too appealing.

One little thing that's bothering me is that I'm getting dropouts on the coax input when connected to my cable box. This has never occurred in the past with any of my other DACs and there were no problems whatsoever listening to the SB Touch through the BNC input. I doubt very much that the cable box is at fault(it was working fine all day) but I'll try doing a reset just to make sure.

Bill O'Connell · « **Reply #190 on:** 31 Dec 2010, 06:24 am »

T&C,

It could be the jitter coming out of the cable box, this DAC hates jitter.

Kinger · « **Reply #191 on:** 31 Dec 2010, 01:14 pm »

Forgive my ignorance here, but is there a way to take the output from a SB Touch to the AES/EBU input of the EE DAC or am I best to just go from coax out on the Touch to coax in on the DAC which is what I'm doing currently. Thought I remember Bill mentioning that the DAC sounds best through AES/EBU, but I could be imagining things.

Bill O'Connell · « **Reply #192 on:** 31 Dec 2010, 02:19 pm »

I'm not sure in a blind test if I could pick out which digital input was being used.I know I can't tell between coax and BNC.
At an earlier time, I tried USB into a Trends converter and then ran the AES out of the Trends into the AES of the DAC and really liked what I was hearing.Could have been because the USB cable was the Axis from Lee and I had him make me up a set of matching Axis Balanced cables and I just used one of the balanced cables as the AES cable and had terrific results with this configuration.

Downsize · « **Reply #193 on:** 31 Dec 2010, 02:55 pm »

Quote from: Kinger on 31 Dec 2010, 01:14 pm

Forgive my ignorance here, but is there a way to take the output from a SB Touch to the AES/EBU input of the EE DAC or am I best to just go from coax out on the Touch to coax in on the DAC which is what I'm doing currently. Thought I remember Bill mentioning that the DAC sounds best through AES/EBU, but I could be imagining things.

You only use pins 2 and 3 on the AES/EBU cable, so you could just attach a 3 pin XLR connector on the end of your coax cable, and that would allow you to use the AES input on your DAC.

Downsize · « **Reply #194 on:** 31 Dec 2010, 02:58 pm »

Quote from: Bill O'Connell on 31 Dec 2010, 02:19 pm

I'm not sure in a blind test if I could pick out which digital input was being used.I know I can't tell between coax and BNC.
At an earlier time, I tried USB into a Trends converter and then ran the AES out of the Trends into the AES of the DAC and really liked what I was hearing.Could have been because the USB cable was the Axis from Lee and I had him make me up a set of matching Axis Balanced cables and I just used one of the balanced cables as the AES cable and had terrific results with this configuration.

Comparing Coax and BNC would probably be nearly impossible .... USB is not on the same sound quality level as the other inputs though, and you CAN hear that difference fairly easily.

Bill O'Connell · « **Reply #195 on:** 31 Dec 2010, 03:09 pm »

Yes, but there was a lovely synergy and tone to the music that the cables were probably injecting in some way or another. Heck, I still use this configuration sometimes running Pure Music on my Macbook Pro and I can assure you the quality is outstanding.

srb · « **Reply #196 on:** 31 Dec 2010, 03:14 pm »

I had read that at least one person used an XLR to RCA adapter to go from S/PDIF RCA coax to AES/EBU and claimed it sounded better, but that didn't really make any sense to me.

S/PDIF coax is 75 ohm single ended and AES/EBU is 110 ohm balanced. You would think that would be a bad mismatch without a matching transformer such as is available from Neutrik and others. But ..... ?

Steve

ted_b · « **Reply #197 on:** 31 Dec 2010, 03:16 pm »

Quote from: srb on 31 Dec 2010, 03:14 pm

I had read that at least one person used an XLR to RCA adapter to go from S/PDIF RCA coax to AES/EBU and claimed it sounded better, but that didn't really make any sense to me.

S/PDIF coax is 75 ohm single ended and AES/EBU is 110 ohm balanced. You would think that would be a bad mismatch without a matching transformer such as is available from Neutrik and others. But ..... ?

Steve

Steve,
I protested too, but Wayne explained, earlier in this thread, that the EE DAC has an impedance transformer internal that handles the 75/110 switch.

Kinger · « **Reply #198 on:** 31 Dec 2010, 03:22 pm »

Thanks for the comments guys. Can anyone provide me with a link to one of these coax to a 3 pin XLR cable connections?

Downsize · « **Reply #199 on:** 31 Dec 2010, 03:23 pm »

I personally think Bill is on to something .... While I am using an Off Ramp converter, and that makes it really hard to say how much that is affecting the sound, I can tell you that switching different digital cables out going to the DAC makes very audible and interesting changes to the sound.

It is readily apparent the DAC does not really sound it's best when used with just a USB cable, and that adding a quality digital cable makes a pretty big difference.