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aberdeencomponents
2005-08-05, 10:16
000000000000000000000

pfarrell
2005-08-05, 11:10
On Fri, 2005-08-05 at 10:16 -0700, aberdeencomponents wrote:
> We specialize in TacT Audio component mods. We use only the digital
> section of the SB2.
> [snip]
> Come see us at www.aberdeencomponents.com

Hmmm, are blatant advertisements by commercial firms allowed
as part of our Acceptable Use Policy?

Being commercial is not bad in the OpenSource world, but
I'd think you'd have to post parts lists, instructions, and
then casually mention that you're willing to do it
for a low low fee if someone doesn't want
to take a hacksaw to a perfectly good SB2.

--
Pat
http://www.pfarrell.com/music/slimserver/slimsoftware.html

seanadams
2005-08-05, 11:29
Hmmm, are blatant advertisements by commercial firms allowed
as part of our Acceptable Use Policy?


He emailed me the pics and I invited him to post it. Personally I don't have a problem with a modest volume of commercial traffic but if we'd rather not hear about stuff like this that's fine too... speak up if you care one way or the other!

Dave D
2005-08-05, 12:09
When I saw the hacking, my first thought was, "NOOOOOOO!!!"

It's a bit interesting, though, to see what people are paying others to do. Doesn't bother me. If I started seeing a bunch of spam about other products, It would get annoying.

Geez, they cut it in half...a perfectly good Squeezebox...

I wonder if this would void the warranty ;)

Robin Bowes
2005-08-05, 12:34
seanadams wrote:
> pfarrell Wrote:
>
>>Hmmm, are blatant advertisements by commercial firms allowed
>>as part of our Acceptable Use Policy?
>>
>
>
> He emailed me the pics and I invited him to post it. Personally I don't
> have a problem with a modest volume of commercial traffic but if we'd
> rather not hear about stuff like this that's fine too... speak up if
> you care one way or the other!

My 0.01:

He's not doing anything that Vinnie @ Red Wine audio is doing, and I
don't have a problem with that either!

R.

seanadams
2005-08-05, 13:07
Did you consider also removing the digital section so we can be more RIAA friendly?

pfarrell
2005-08-05, 13:19
On Fri, 2005-08-05 at 12:56 -0700, aberdeencomponents wrote:
> This aint no advertising,
> I was just showing one of the many things "Tact Hackers" do to the SB2,
> if you got to my site you see nothing about SB2.

Yeah, that did confuse me.

> I do it for free. As far as parts goes , you just need a Hacksaw.
> the only thing we are eliminating is the COMPLETE analog section, which
> we dont use.

I think I didn't understand exactly what you were doing.

> Arent you in the wrong part of the Forum? Your open source, I am
> audiophile.

Forum? I'm on the mailing list, which is mirrored to the forum.
Many of us follow several lists or sections of the forums.
There is natural overlap.

Wouldn't a coping saw do a better job than a hacksaw with your
proposed mod?

I'm not a purist on advertising, but I think guidelines are
useful. Of course, some of the other mailing lists could
probably use moderators to kill troll threads.


--
Pat
http://www.pfarrell.com/music/slimserver/slimsoftware.html

Aylwin
2005-08-06, 00:23
Interesting stuff! Looking at the photo with the hack saw I can't help but wince. It looks painful. But the photo with the board cut in two is amazing. You mean it still works?

So what do you with the half that still works? Stick it in a TacT box? Any pictures?

JJZolx
2005-08-07, 12:24
Yes it still works and sounds great.
The Mod is not finished.... I have to make 2 more major cuts, the unit will be the size of a deck of cards when it done.
1st cut removed the entire analog section. 2nd cut will remove the 14 volt power supply. 3rd cut will remove the front end power supply (5v, 3,3 v).

Is it _necessary_ to chop up the board to enable you to bypass the analog and power supply sections? Or just dramatic?

Might be some food for thought here for Slim Devices. I've wondered whether some small DAC makers would be interested in dropping the communication end of an SB into a DAC. If the SB motherboard were actually two or three boards it would make this very easy. I think it would also aid in the production of "audiophile" versions of the SB, with upgraded analog output boards and power supplies, as well as making it easier to isolate/sheild the different sections within the chassis.

seanadams
2005-08-07, 23:14
Is it _necessary_ to chop up the board to enable you to bypass the analog and power supply sections? Or just dramatic?

Might be some food for thought here for Slim Devices. I've wondered whether some small DAC makers would be interested in dropping the communication end of an SB into a DAC. If the SB motherboard were actually two or three boards it would make this very easy. I think it would also aid in the production of "audiophile" versions of the SB, with upgraded analog output boards and power supplies, as well as making it easier to isolate/sheild the different sections within the chassis.

I think you are underestimating the performance of the built-in DAC. Check out this test where Squeezebox2 outperforms a standalone DAC (complete with differential PS and separate burr-brown chips for each channel):

http://www.seanadams.com/sb2_super_regs/

In fairness to the Adcom DAC, it's a few years old.

In fairness to SB2 (vs recent $1000+ DACs which might perform better), it does a hell of a lot more than D->A conversion at a fraction of the price.

Patrick Dixon
2005-08-08, 00:33
Which filter mode are you using in the DAC, Sean?

Fifer
2005-08-08, 00:54
Sean, 'SB2, 5V & 9V regs from int', can you give us more details?

Patrick Dixon
2005-08-08, 01:10
I think that means with the 5V & 9V regulators fed by the internal (14V) supply.

seanadams
2005-08-08, 08:37
Which filter mode are you using in the DAC, Sean?

Using the default, sharp roll-off

seanadams
2005-08-08, 08:37
I think that means with the 5V & 9V regulators fed by the internal (14V) supply.

Right, the super regs, that is.

pfarrell
2005-08-08, 08:48
On Sun, 2005-08-07 at 23:14 -0700, seanadams wrote:
> In fairness to SB2 (vs recent $1000+ DACs which might perform better),
> it does a hell of a lot more than D->A conversion at a fraction of the
> price.

As tempting as the SB2 is, I've got three Sb1's and haven't been in a
hurry to replace them. My uninformed guess is that replacing a SB2's dac
with a mid-fi standalone DAC is not worthwhile, the SB2 parts are
quality and Sean &co are smart. But Sean's comment raises a possibility.

If some SB2 user in the Washington DC area is interested in a test,
I could bring my Benchmark DAC-1, and see if we can tell a difference.
Could be a fun way to spend a couple of hours.

My website has email and other contact info, unblinded.

--
Pat
http://www.pfarrell.com/music/slimserver/slimsoftware.html

JJZolx
2005-08-08, 09:37
I think you are underestimating the performance of the built-in DAC.
A guy saws your DAC right off the board, posts the pics, and you're telling me that _I'm_ underestimating its performance? :-)

Fifer
2005-08-08, 10:20
My uninformed guess is that replacing a SB2's dac
with a mid-fi standalone DAC is not worthwhile, the SB2 parts are
quality and Sean &co are smart.
My slightly more informed opinion is that Pat's right. My M-Audio 2496 SuperDAC (if that qualifies as mid-fi) was a significant improvement over the SB1's internal DAC (to my ears of course) but the SB2 sounds much better using the internal DAC compared with using the M-Audio. There's a fair chance that the Benchmark will outperform the SB2 (it should, if price is remotely related to sound quality) but it would be interesting to know where the cross-over point is on the external DAC price continuum.

A thought occurs [lightbulb: on]. Have Slim Devices given any thought to equipping the SB2 with a digital input? Given that the internal DAC appears to be a minor miracle at it's price point (maybe not so minor), it might be nice to use it for the benefit of other kit located nearby.

John Stimson
2005-08-08, 15:19
Sean, what are you using as "super-regulators"? Is there a thread or a web page describing that modification?

seanadams
2005-08-08, 15:38
Sean, what are you using as "super-regulators"? Is there a thread or a web page describing that modification?

Those are Andrew Weekes' regulators, discussed here previously

http://www.alw.audio.dsl.pipex.com/

WK446
2005-08-08, 15:49
I am currently running a SB2 with an Audio Mirror DAC D1, which is a non-oversampling DAC. I find the sound quality noticeably superior to that of the built-in DAC of the SB2. I also own the Benchmark DAC-1 and can echo that it also sounds superior to the internal unit of the SB2.

What has impressed me the most about the SB2 is it's jitter performance, which IMHO is truly superb.

My hat is off to the Slim staff for giving us the choice between internal and external DACs.



On Sun, 2005-08-07 at 23:14 -0700, seanadams wrote:
> In fairness to SB2 (vs recent $1000+ DACs which might perform better),
> it does a hell of a lot more than D->A conversion at a fraction of the
> price.

As tempting as the SB2 is, I've got three Sb1's and haven't been in a
hurry to replace them. My uninformed guess is that replacing a SB2's dac
with a mid-fi standalone DAC is not worthwhile, the SB2 parts are
quality and Sean &co are smart. But Sean's comment raises a possibility.

If some SB2 user in the Washington DC area is interested in a test,
I could bring my Benchmark DAC-1, and see if we can tell a difference.
Could be a fun way to spend a couple of hours.

My website has email and other contact info, unblinded.

--
Pat
http://www.pfarrell.com/music/slimserver/slimsoftware.html

corwin
2005-08-17, 18:55
I see no problem with some commercial traffic here as it relates to mods to the SB2. Seems to be quite a wave of these recently.

joshk
2005-08-22, 07:49
Aberdeen,

Do you mind sharing what specific transformer you are using? Curious minds want to know.

void
2005-08-23, 13:11
The best transformer known, the SC947-02
According to them. Not everyone agrees that they are the best. We're doing some tests with different transformers including the one you mention, it will take at least few weeks more before I can say something about our experiences, the way you implement them makes a great difference.

joshk
2005-08-24, 07:26
Thanks! The 939-07 is quite interesting too!

pfarrell
2005-08-25, 21:12
On Tue, 2005-08-23 at 13:11 -0700, void wrote:
> aberdeencomponents Wrote:
> > The best transformer known, the SC947-02
> According to them. Not everyone agrees that they are the best.

Have to agree with void on this one. Transformers are
either very efficient at one frequency, or very inefficient.
Since audio reproduction by its nature needs frequency response
of at least 20hz to 20Khz (and some would save from 10hz to 100Khz)
selecting transformers is an art.

The recording studio engineers get into long and heated
discussions of which transformer sounds "best" on a particular
(track) recording.

Using a transformer on a high frequency square-wave, as most
digital audio things are, seems strange to me. The before and after
shots of a square-wave through a transformer is standard in
oscilloscope 101. Or at least was when I was an undergraduate
years ago.


--
Pat Farrell
http://www.pfarrell.com

Andrew L. Weekes
2005-12-12, 08:55
Digital out. the other picture shows a Scientific Conversions Shielded pulse transformer for the rca digital out.

So not only do you use a shielded transformer, which worsens the mismatch to a purely 75R transmission line, you also use a non-75R RCA plug.

This is supposed to be an improvement in what way exactly?

A transformer is the best way to do a good SPDIF, but I guarantee your implementation cannot be remotely optimal.

Andy.

JJZolx
2005-12-13, 11:07
Given that it's been four months since the original photos, why don't you show us what you've done with that chopped Squeezebox?