Eastern Electric DAC mods

Wayne1 · « **Reply #160 on:** 24 Dec 2010, 04:20 pm »

Acme Audio products

The EE DAC calls for a 5 x 20mm 800ma quick blow fuse. Acme Audio does not sell fuses in this value. For the modded DAC, I used a 1 amp fuse. I feel this is a safe change. If you do not want to risk the extra 0.2amps, I believe HiFiTuning offers quick blow 800ma. Furutech does not.

I have not tried any other fuses in the EE DAC. I have tried Furutech and HiFiTuning in other products. Furutech does not seem to offer quick blow fuses. I would be very careful about using slo-blow in place of quick blow.

In the power supplies I build for the SqueezeBox, I used a HiFiTuning. I did not feel any sound changes were worth the price difference. For a power supply I built for a Mac Mini, Silverlight felt the Furutech was an improvement in his system. Pez tried Acme and Furutech in his DIY SE amp and preferred the Furutech, slightly, but perhaps had too low a value as he blew up a few of them. At $50.00 each he decided to go back to more conventional fuses.

Again, this is an area where you will have to experiment. There appears to be a different synergy with each system. I will be getting 1 amp 5 x 20mm fuses in stock within a week or so. I will note on here and on my website when they have arrived.

The AES input does have transformer in the circuit to convert balanced 110 ohm to single ended 75 ohm. I would not use an adapter that wires pin 1 and pin 3 together. Pin 3 should be left unconnected. Pin 2 should be for signal and pin 1 for ground.

The AES input circuit also has attenuation built into it to lower the "hotter" pro audio RF levels down to consumer levels. Perhaps the same purpose could be achieved by using the inline attenuators that John Kenny suggested from Minicurcuits. This might be a preferred option rather than deliberately mismatching impedances.

ted_b · « **Reply #161 on:** 24 Dec 2010, 04:21 pm »

Quote from: Turnandcough on 24 Dec 2010, 03:19 pm

I'm thinking about giving this a try. I'm using a BNC cable from my Touch and I'm not sure which adapter (cheater plug) I need to get(wired or unwired?).

http://www.fullcompass.com/product/302172.html
http://www.fullcompass.com/product/340728.html

Also - does anyone have a link for the Acme Audio fuse?

It doesn't make any sense to me that either of these ANALOG connectors will work. To go from S/PDIF to AES/EBU always requires a 75 ohm to 110 ohm impedance transformer, like this one...
http://www.performanceaudio.com/cgi/product_view.cgi?products_id=537

Edit: oops, did not know that the EE DAC does the impedance change automatically? I'd still use the correct ones, but maybe I'm wrong.

But really, if I were you I'd use a good S/PDIF cable with BNC and forego the extra connectors. I think a Black Cat Veloce ($123) direct from SB to EE DAC (BNC input) would be better than an inferior S/PDIF cable and XLR converter into AES/EBU. In my eval I didn't find a huge difference between inputs, given good cables. Yes, i eventually settled on the AES/EBU but I like that sturdier connection anyway, given a coin toss......yours may not be a coin toss.

Wayne1 · « **Reply #162 on:** 24 Dec 2010, 04:29 pm »

Ted,

You are correct. To do it right, the 75 ohm impedance of the output and cable of the source should be changed to 110 ohm. Then the transformer inside the EE DAC will change that back to 75 ohm and attenuate the signal level. Lots of extra stuff in the signal path.

What I was trying to say in my earlier post is that perhaps the improvement that is spoken of is caused by the attenuation of the signal levels. As you can do the same thing using the Minicircuits attenuators for $10.00 each, it is an inexpensive experiment.

Downsize · « **Reply #163 on:** 24 Dec 2010, 06:25 pm »

Quote from: Wayne1 on 24 Dec 2010, 04:20 pm

Acme Audio products

The EE DAC calls for a 5 x 20mm 800ma quick blow fuse. Acme Audio does not sell fuses in this value. For the modded DAC, I used a 1 amp fuse. I feel this is a safe change. If you do not want to risk the extra 0.2amps, I believe HiFiTuning offers quick blow 800ma. Furutech does not.

I have not tried any other fuses in the EE DAC. I have tried Furutech and HiFiTuning in other products. Furutech does not seem to offer quick blow fuses. I would be very careful about using slo-blow in place of quick blow.

In the power supplies I build for the SqueezeBox, I used a HiFiTuning. I did not feel any sound changes were worth the price difference. For a power supply I built for a Mac Mini, Silverlight felt the Furutech was an improvement in his system. Pez tried Acme and Furutech in his DIY SE amp and preferred the Furutech, slightly, but perhaps had too low a value as he blew up a few of them. At $50.00 each he decided to go back to more conventional fuses.

Again, this is an area where you will have to experiment. There appears to be a different synergy with each system. I will be getting 1 amp 5 x 20mm fuses in stock within a week or so. I will note on here and on my website when they have arrived.

The AES input does have transformer in the circuit to convert balanced 110 ohm to single ended 75 ohm. I would not use an adapter that wires pin 1 and pin 3 together. Pin 3 should be left unconnected. Pin 2 should be for signal and pin 1 for ground.

The AES input circuit also has attenuation built into it to lower the "hotter" pro audio RF levels down to consumer levels. Perhaps the same purpose could be achieved by using the inline attenuators that John Kenny suggested from Minicurcuits. This might be a preferred option rather than deliberately mismatching impedances.

Woah ... Now I am confused a bit Wayne.

I thought it had been positively determined the AES/EBU input sounded better than ANY of the other inputs ??? How is this the case if the AES input has a converter built in to it ?

And one more question please : Since the AES input converts the signal back to a 75ohm one, does that mean a 75ohm coax cable with AES XLR connectors will be able to be used instead of more special 110ohm wire, and still sound equal ???

I should add that I am using an Off Ramp with a 110 ohm output, so it would be a true 110 ohm cable without ANY kind of adapters or attenuators.

Wayne1 · « **Reply #164 on:** 24 Dec 2010, 07:33 pm »

I was not aware of any definitive comment that the AES input sounded "better". I think Bill O'Connell stated that he liked the way it sounded going into the AES input.

My thoughts are that the attenuation used in the AES input might be what is making it sound "better"

AES digital is not the best method for RF distribution. A well designed coax is better than a shielded twisted pair when you are talking transmission at mHz.

When Sean Adams designed the Transporter, he felt that the AES connections were the worst. He just added them because of customer requests.

All the digital inputs go through the same switch and then into the DAC. The "best" thing to do would be to bypass the switch and run direct.

ted_b · « **Reply #165 on:** 24 Dec 2010, 08:23 pm »

Wayne,
I think he's also referencing the reviews. Stereomojo, for example, also states that the AES/EBU input is his/their favorite on the EE.

Downsize · « **Reply #166 on:** 25 Dec 2010, 01:12 am »

Quote from: ted_b on 24 Dec 2010, 08:23 pm

Wayne,
I think he's also referencing the reviews. Stereomojo, for example, also states that the AES/EBU input is his/their favorite on the EE.

Well, yes Ted .... and more people too. I believe Bill also claims that the AES sounds better. I just want to know which one, AES or BNC, where I can go ahead and finalize my cables for my system.

Turnandcough · « **Reply #167 on:** 25 Dec 2010, 01:29 am »

I have some overpriced Rothwell -10 dB attenuators lying around somewhere. I'll probably order a BNC/XLR anyway and compare. There's no rush as I have yet to order the DAC. I'm just studying all the options and related costs before I hit the "add to cart/proceed to checkout" buttons.

Gopher · « **Reply #168 on:** 29 Dec 2010, 05:32 pm »

The modified DAC was just delivered to my office! I guess they couldn't get it here on the 28th due to the crazy weather Long Island got, but I'm looking forward to doing some listening after work.

Also, I had a thought and am going to re-visit the Pavane tube in the stock DAC with a different IC (Wywire v2) which might be more complimentary to that tubes signature.

Looking forward to experimenting!

Downsize · « **Reply #169 on:** 29 Dec 2010, 08:06 pm »

Are there any online instructions for bypassing the volume control ? I just need to know which two wires to jumper together.

Can I assume to attenuate the volume, all you do is add a resistor inline ?

Wayne1 · « **Reply #170 on:** 29 Dec 2010, 08:26 pm »

There are cables that go from the circuit board to the volume control and then back to the output connectors. I remove the cables and run leads from the circuit board direct to the jacks.

An "L-Pad" resistor network could be installed at the output jacks.

Downsize · « **Reply #171 on:** 29 Dec 2010, 09:57 pm »

Quote from: Wayne1 on 29 Dec 2010, 08:26 pm

There are cables that go from the circuit board to the volume control and then back to the output connectors. I remove the cables and run leads from the circuit board direct to the jacks.

An "L-Pad" resistor network could be installed at the output jacks.

Thank you Wayne ...

It would be MUCH easier if I could figure out how to lower the gain on my new laptop... LOL
I just HAD to buy the expensive and fancy HP .... I have NO idea why, but it has so many volume controls it is crazy ! No matter whatI do, I can not get the volume to go low enough .... Even when it says it is on "1", it is still reasonably loud, and that is with my EE DAC's volume set to only 6:00 o' clock. I SUCK AT COMPUTERS !!!

Downsize · « **Reply #172 on:** 30 Dec 2010, 01:28 am »

Well ... I never did get any kind of definitive answers aboout which EE DAC input sound best, the BNC or the AES/EBU .... So I decided to find out for myself.

I made two cables, both using my 97/3 % silver/gold alloy conductors. One is a coax of course, and the other a 110 ohm twisted pair cable. In a few weeks, I will report back my findings

Turnandcough · « **Reply #173 on:** 30 Dec 2010, 01:42 am »

Quote from: Wayne1 on 29 Dec 2010, 08:26 pm

There are cables that go from the circuit board to the volume control and then back to the output connectors. I remove the cables and run leads from the circuit board direct to the jacks.

An "L-Pad" resistor network could be installed at the output jacks.

I'm anxiously expecting mine tomorrow. After some tube rolling bypassing the volume control is the first thing I'd like to do.
Forgive my ignorance but does an L-pad consist of a resistor and a cap in series between the +/- of each output terminal or is it a resistor on the + lead with another going across + and - ? What values would be a good starting point?

Wayne - please let me know if this subject is inappropriate for the Bolder circle.

Wayne1 · « **Reply #174 on:** 30 Dec 2010, 01:58 am »

An L-pad is a resistor across the + and - and one in series with the signal + lead.

The values would be determined by the impedance of what you are sending the signal into and how much attenuation you would need.

There are various calculators to figure this out on the web.

Tube rolling and changing the fuse will have a large effect on the sound of the DAC and won't void the warranty.

setamp · « **Reply #175 on:** 30 Dec 2010, 02:00 am »

I'm not sure if this is the correct forum to ask this question. I am getting a lot of dropouts with my EE Minimax Dac. I am feeding it with the digital out of my Music Hall Maverick CDP via coax cable. I suspect the Maverick is the culprit as I have not heard of largescale dropout problems with this dac. I am considering moving to a Mac Mini music server/ HiFace spdif setup in hopes this will end these annoying dropouts. Is this considered to be a good quality source or is there a better transport I should consider? Thanks

Wayne1 · « **Reply #176 on:** 30 Dec 2010, 03:05 am »

I can't say what would be a better transport, but I have not had any problems using a SqueezeBox 3, Duet receiver or Touch into the EE DAC. I have not experienced any dropouts with any of those sources.

I also use an inexpensive Insignia Blu-ray player into the EE DAC for DVD, Blu-ray and Netflix. Never had a problem with that as a source, either.

I have used the M2Tech HiFace from my laptop PC into the EE DAC to check out higher res playback. No problems with that, either. I did prefer the sound of the modded SqueezeBox transports to the Hi-Face/laptop combo.

You may want to try a different cable from your CD player into the DAC.

Downsize · « **Reply #177 on:** 30 Dec 2010, 04:00 am »

Quote from: Wayne1 on 30 Dec 2010, 01:58 am

An L-pad is a resistor across the + and - and one in series with the signal + lead.

The values would be determined by the impedance of what you are sending the signal into and how much attenuation you would need.

There are various calculators to figure this out on the web.

Tube rolling and changing the fuse will have a large effect on the sound of the DAC and won't void the warranty.

Hi Wayne .... Any chance you would provide a link to one of those calculation sites ? I would just love to remove the volume control from my EE DAC, but it is WAAAAAAAAAAAAAAAAAAAY too loud without it.

Thanks

Wayne1 · « **Reply #178 on:** 30 Dec 2010, 04:07 pm »

Here is a simple calculator
http://www.troester.org/ls/lpad.html

Here is a good explanation of how to design an attenuation network.

http://www.uneeda-audio.com/pads/

I would suggest building the network into a cable, first, to fine tune the values. This would also give you a chance to listen to see if there are any downsides to using the resistor network. You can try different brands of resistors to see if there is any audible difference.

After all the evaluations, then you can start ripping apart your DAC.

Another option would be to lower the gain of the output tube. That gets a bit more involved.

Downsize · « **Reply #179 on:** 30 Dec 2010, 04:14 pm »

Quote from: Wayne1 on 30 Dec 2010, 04:07 pm

Here is a simple calculator
http://www.troester.org/ls/lpad.html

Here is a good explanation of how to design an attenuation network.

http://www.uneeda-audio.com/pads/

I would suggest building the network into a cable, first, to fine tune the values. This would also give you a chance to listen to see if there are any downsides to using the resistor network. You can try different brands of resistors to see if there is any audible difference.

After all the evaluations, then you can start ripping apart your DAC.

Another option would be to lower the gain of the output tube. That gets a bit more involved.

Thank you Wayne ... You are very giving with your time and knowledge. A true gem in the world of audio ! I'm lifting one to you tonight