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Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 KHz

TNT

Member
Joined 2003
Paid Member
If one really get a soundstage listening via headphones, as in something reassembling a acoustic event in front of you, I can assure You that this system is SEVERELY FLAWED for using with speakers. So please only tailor a dedicated HP amplifier for this. Don't try to accomplish it for a output intended for speaker use. And if you do, don't advertise it as a combined output.

Then people might confuse "headphone stage" with low distorsion but thats something else....

//
 
Member
Joined 2005
Paid Member
And I'm not looking to be doing just "very well", I'm targeting to be the best possible :)

I also want to use some of the parts I already have on whole reels, although I'm hoping that the dac1101 will take care of that by itself....

In that case please don't go the no feedback route and make this a MyFi product :D

Although no feedback is a contradictio in terminis to begin with, there's no such thing.

If you don't intend to tie a global loop around the output buffer (G~1) keep in mind that most headphone cables show a good bit of cable capacitance, so you'll be creating all sorts of problems (high freq. roll-off, ringing on fast transients, instability, etc.) that go away with a global loop tied around the output stage.
 
Member
Joined 2005
Paid Member
If one really get a soundstage listening via headphones, as in something reassembling a acoustic event in front of you, I can assure You that this system is SEVERELY FLAWED for using with speakers. So please only tailor a dedicated HP amplifier for this. Don't try to accomplish it for a output intended for speaker use. And if you do, don't advertise it as a combined output.

Then people might confuse "headphone stage" with low distorsion but thats something else....

//

The issue here is that with a headphone you do not get the additional auditory feedback from the room (reflections, room modes, etc. etc.) which indeed could lead to the impression (!) of a different soundstage, however this is all between the ears (literally!). There's absolutely no reason why a headphone output would do anything different than a line output.
 

TNT

Member
Joined 2003
Paid Member
The issue here is that with a headphone you do not get the additional auditory feedback from the room (reflections, room modes, etc. etc.) which indeed could lead to the impression (!) of a different soundstage, however this is all between the ears (literally!). There's absolutely no reason why a headphone output would do anything different than a line output.

This was my point. Poor channel separation is probably good for HP listening - cross feed solutions come to mind - but not good for speaker use. This is one example.

//
 
I'm using HD800 (non-s) on the buffered outputs (balanced driven from the pair of dam1021's) it sounds very good, not artificial at all. When using filters like NewNOS it removes much of the brightness they suffer from. In all a good (and very satisfying) combination, although a discrete output would be better. Keep in mind that there is absolutely no crosstalk, which can take some getting used to, it doesn't replace loudspeaker listening for soundstage no matter what headphones you use.
 
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O.k., I joined the party last week and ordered a DAM after sneaking around it from the beginning. I was a little put off because of all this digital stuff, and tiny SMT parts. I prefer to handle tubes, chokes and big capacitors:p
So, the Dac sounded pretty uninvolving initially, flat, harsh and uninvolving, but it opened up considerably after some continious operation. Power supply is a simple 12V LM317/327 so far, but Salas Shunts are waiting to be connected.

It has a great potential for sure, thanks to Sören for this well thought out product and the affordable price. And for his patience with all those crazy tweakers here;)

But I have to admit that I can not wrap my head around the serial connection.
I have read all the pages and still do not get it. So, simple question hoping for simple answers:
Which cable do I need, or adapter, or whatever; to connect the DAM with a Windows Surface Pro, which only has a USB Input, no Serial?
Best would be a link to Ebay or Amazon.
It really drives me nuts, was busy with this for many hours:dead:
So, Gentlemen, any help is greatly appreciated...
 
O.k., I joined the party last week and ordered a DAM after sneaking around it from the beginning. I was a little put off because of all this digital stuff, and tiny SMT parts. I prefer to handle tubes, chokes and big capacitors:p
So, the Dac sounded pretty uninvolving initially, flat, harsh and uninvolving, but it opened up considerably after some continious operation. Power supply is a simple 12V LM317/327 so far, but Salas Shunts are waiting to be connected.

It has a great potential for sure, thanks to Sören for this well thought out product and the affordable price. And for his patience with all those crazy tweakers here;)

But I have to admit that I can not wrap my head around the serial connection.
I have read all the pages and still do not get it. So, simple question hoping for simple answers:
Which cable do I need, or adapter, or whatever; to connect the DAM with a Windows Surface Pro, which only has a USB Input, no Serial?
Best would be a link to Ebay or Amazon.
It really drives me nuts, was busy with this for many hours:dead:
So, Gentlemen, any help is greatly appreciated...

Add some capacitance to the vref's as described here in detail.

For serial you simply need an FTDI or equiv 3.3V USB to TTL converter, simply connect the pins to the TTL serial headers and isolated GND. You'll also have to supply 3.3V to the isolated headers if not already done so.

I personally use these, however keep in mind they're probably fake FTDI chips, which work fine in Linux, however FTDI has been known to release drivers that break counterfeit chips in Windows.
http://www.ebay.ca/itm/FT232RL-3-3V...421597?hash=item58cbafda5d:g:jk8AAOSwrklVMjIp
 
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Ok, thanks, one step forward. I saw these already; and found some with cable, for example this one:

http://www.amazon.de/PL2303TA-RS232-Konverter-Serial-Cable/dp/B00T60QTUK/ref=pd_sim_147_3?ie=UTF8&dpID=41h8GKXazkL&dpSrc=sims&preST=_AC_UL160_SR160%2C160_&refRID=1A7JJ6D6ZRGNHRM3C3JQ


Does this work too?
It has another chip, but works with 3.3 Volt and seems to be compatible with Windows 8.1. Btw 3.3V are connected to the isolated I2s Input via Salas shunt.
And downloaded Extra Putty already, I think I could manage this once the connection is made.

And for Vref: I have REV3, so it has already bigger caps, but maybe I try some Oscons i have at hand on top of the existing ones. Also plan to use Shunts for +-5V, as the Vref seems to be most critical.
But first to the filters...
 
Since Firmware 1.0.5 (DAM v.1, Amanero) I have the following minor issue:
When I start playback too early after powering up the DAM stays mute.

If I wait until the L000 has appeared and start playback then all works fine.
Code:
R1.05
I3
L000
F4
V+00
I3
I0
L192
L000
I0
L192
But If I start playback before, the DAM looks but stays mute
Code:
R1.05
I3
L000
F4
V+00
I3
I0
L192
L192
 
just a fun fact

on 26 feb 15 i had ordered 2 x dam1021-05: 0.05% resistor version
which was 372.08 EUR

if i put this order in today it would be 469.12 EUR
and the parts count is much less on the r3 boards?

Yes, I sold the first batch too cheap, I'm an optimist and didn't realize how much work the firmware really is....

And in the meantime the USD/EUR exchange rate have changed.... And the cost of 100 pcs 0603 1% resistors is like $0.10 :)
 
Yes, I sold the first batch too cheap, I'm an optimist and didn't realize how much work the firmware really is....

And in the meantime the USD/EUR exchange rate have changed.... And the cost of 100 pcs 0603 1% resistors is like $0.10 :)

im sure the firmware was and is a major pita
but the exchange rate only changed less than 4% in the last 12mts and theres 10$ less resistors on new boards and now your discontinuing 0.05 versions
meaning the base model price is now 35% more
i would very much doubt the difference in the resistor price of these two models is 62e

at 238e for base model is a mile away from the 137e first announced as r2r been brought to the masses

you have me worried your lining up a pricing scheme in an attempt to justify over pricing of the to be released 1121 as well