My Silverstone EB-01 mods

[fordgtlover]

I bought a Silverstone EB-01 after reading through the posts here at head-fi. I came highly rated at its pricepoint.

Being a tinkerer I thought about modding it. Not knowing a lot about electronics, but having built a few amps I decided that I would replace the standard BB OPA604 op-amps with my favourite, the AD8610.

This worked well and seemed to offer more clarity in the mids.

Realising that I would not really be able to mod much more without potentially detroying it, I decided to upgrade the standard no-name electrolytic caps with my favourite - the highly regarded Panasonic FM range. Unable to find an FM in 25V 10uf, I put a small Elna silmic in that spot (Mmmmm .... boutique

) In all fairness there were a few United Chemi-con KY series caps in amongst the original cheapies.

The replaced caps are:
10 x 16V 100uf
2 x 16V 1000uf
1 x 25V 10uf
2 x 50V 22uf

I don't know why these aren't all 6.3V caps because the DAC runs off USB power. Oh well, I swapped like for like.

I really like the sound of my little EB-01. I use FLAC files through USB to the EB-01 to my M³ for boost and out through my K701 - very nice.

Here are some piccies. The first is an image of the stock EB-01 I 'borrowed' from a website. The second is after the op-amp replacements, and finally the last is after the cap surgery.

 

[joe_cool]

Did you measure the power supply voltages on the OPA604 opamps? I don't think they will work well at 5 volt supply.

 

[fordgtlover]

The standard opamps were the OPA604, I put in the AD8610. I was a little concerned that they might not work too well because, as I understand, they require more voltage that the OPA604, but they seem to work fine.

No I haven't measured the voltages, but I will tonight.

 

[joe_cool]

According to Tangent, the AD8610(8620) works well as low as 7.6 volts total where the OPA604(2604) requires 11.4 volts (both tests at 2.0 Vrms output).

So I'm just interested to know how the opamps are employed in this application. It's possible there is a voltage converter somewhere in the circuit to provide a negative voltage for the analog section.

 

[fordgtlover]

Between pins 4 & 7 I read 14.07V.

I have no idea where this voltage comes from.

I guess this would explain why the caps aren't 6.3V though.

The OPA604 sheet indicates supply voltage from 4.5V up to 24V, while the AD8610 requires dual 5V to 13V.

Tangent descibes the OPA604 as sonically similar to the OPA2134, which is not my favourite.

 

[joe_cool]

Obviously there is some sort of switching regulator supplying the +/- 7 volts to the analog section. I suspected as much. The AD8610s should give you a much stronger midrange sound. The OPA134/604 is known for smoother (recessed) midrange.

 

[fordgtlover]

That would explain the inductor. I was curious what that was there for. It's boosting the voltage from 5V to 7V.

I'm sure to anyone with electronics knowledge they would have picked up on that immediately.

 

[fordgtlover]

Thanks for the heads up. I have learned something here.

 

[ttan98]

Quote:

Originally Posted by fordgtlover /img/forum/go_quote.gif I bought a Silverstone EB-01 after reading through the posts here at head-fi. I came highly rated at its pricepoint. Being a tinkerer I thought about modding it. Not knowing a lot about electronics, but having built a few amps I decided that I would replace the standard BB OPA604 op-amps with my favourite, the AD8610. This worked well and seemed to offer more clarity in the mids. Realising that I would not really be able to mod much more without potentially detroying it, I decided to upgrade the standard no-name electrolytic caps with my favourite - the highly regarded Panasonic FM range. Unable to find an FM in 25V 10uf, I put a small Elna silmic in that spot (Mmmmm .... boutique ) In all fairness there were a few United Chemi-con KY series caps in amongst the original cheapies. The replaced caps are: 10 x 16V 100uf 2 x 16V 1000uf 1 x 25V 10uf 2 x 50V 22uf I don't know why these aren't all 6.3V caps because the DAC runs off USB power. Oh well, I swapped like for like. I really like the sound of my little EB-01. I use FLAC files through USB to the EB-01 to my M³ for boost and out through my K701 - very nice. Here are some piccies. The first is an image of the stock EB-01 I 'borrowed' from a website. The second is after the op-amp replacements, and finally the last is after the cap surgery.

Can you provide us the name A/D chipset it using and the clocking chip?

thanks

 

[fordgtlover]

It uses a PCM2702E. The chip identified as U1 (just under the blue relay) is an NE555. I can't make out the numbers on U7 and U8.

 

[Bjornboy81]

Ever think about using an external PS? As soon as I get mine, I'd like to take a look at this option. Disconnect the switched internal PS and use a Wall wart or STEPS to provide the analog power. May require cutting foils though

Looks good though!

 

[fordgtlover]

I actually tinkered with injecting 12V into the USB power using the following approach, but couldn't get it working

USB...........................................DAC

Signal ========================
Power ======== ╔============
==============12V input

 

[Bjornboy81]

probably because of that step up converter...it was seeing an over voltage condition.

 

[fordgtlover]

That makes sense - thanks

Are there any other mods that might be worth considering?

 

[Bjornboy81]

the only ones I can think of are the caps and power supply. From what I've read, this is a pretty capable DAC. Short of changing the D/A chip I think that all you can really do. ....unless you believe better resistors would benefit...

I need to work on getting a better amp before I upgrade the EB01....it'll be a pointless effort otherwise.