Your case is completely different from 99.99999% of all uses. You cannot talk about other uses....only yours. The usual op amp on the output of a DAC does not see 1.8K nor does it need to put out more than 2V. This is what everyone wants....something for their use....not yours. Please talk about what you know works universally, not for your one off use. It serves no one. Your "real world condition" is only yours.....your world only. This is not what others are looking for. The op amps in the Happy one or other CD players/DACs do not drive anything that needs current. You are using the Op amp as the input stage for your amp. That is why you need so much gain and why you have such a low impedance load. Not useful info.
Simple DAC mods that will make your DAC sound like it cost twice as much.
- Thread starter Blizzard
- Start date
In my experience the less something has to work, the better it sounds. The Sonic Imagery's sound the best in every application I've tried them in. Which is why I reccommend them.
Did you read that thread starting at post # 84? He's talking about modding a regular DAC with the 994's.:
"Here is the main criteria for opamp selection for the LKS.
Gain Bandwidth Product (GBW) around 50MHz
LKS uses a combined I/V and first stage low pass filter and it has to deal with a raw input of up to 23MHz (DSD512) so double that to get the bandwidth.
The I/V uses negative feedback to do its work so the opamp has to be fast enough to make the necessary corrections for negative feedback to work (sufficient phase margin for the loop gain LKS designed into the DAC).
This is critical to reduce transient and intermodulation distortion (TID/IMD)
Output current 32mA or more.
The Sabre puts out 32mA@ full scale, and I want only Class-A operation, so opamp idle current needs to be >30mA.
Most DAC chips on the market put out between 2-4mA
Sonic Imagery Ticha 994
GBW: 50MHz OK
Output current: ±150mA OK
Idle current: 30mA almost OK
Some of potential candidates mentioned
NJR Muses02
GBW: 11MHz Not OK
Output current: ±50mA OK
Idle current: 8mA Not OK
LME49720
GBW: 55MHz OK
Output current ±26mA Marginal in one direction
Idle current: 10mA Not OK
Will the 2 above work in practice ?
Sound will come out of the DAC, and it will be the brittle, scratchy and bright top end, that is the common complaint of Delta-Sigma DACs.
In the case of the MUSES02 there is also the midrange suckout at high sampling rates (>88kHz) to deal with because of the insufficient bandwidth.
The harsh sound and smeared transients is in part due to TIM/IMD and the opamp moving between Class-A and Class-B while trying to deliver the large load current coming from the Sabre.
In order to get the liquidity without the harshness so beloved by the R2R crowd, the opamp in the Sabre's I/V converter needs to have the bandwidth/speed and the juice to do its work."
Yes, I read all that. Just one persons opinion about what "he" thinks the circuit needs. Again, just keep to the facts. Now you say you like your fave everywhere, in every circuit you have tried. You should have said this before. Instead you talked about current sinking and class A which you know nothing about. Just tell us what you did and what you heard in ways that make sense to those who need the info. Stop quoting specs and others. Just tell us what you know. Don't pretend to know stuff and don't defend yourself. Just state what you did and what you heard....THIS IS THE ONLY TRUTH THERE IS....YOUR DIRECT EXPERIENCE....not some conjecture about anything.
Your particular case is an exception in the audiophile world. 13.46V signals will produce almost square waves in typical amplifiers
. The typical situation is that real input signals have less than 2V amplitude, as amplifiers have gain around 20-30 dB and modern speakers are reasonably efficient. And most have input impedance's between 5 and 100 Kohm. You should list your special requirements either in your signature or in your profile at WBF. Otherwise your claims will be misinterpreted and misleading.
Microstrip quoted the specs. I was just saying under some conditions those specs won't look so great. For example, my conditions.
Your particular case is an exception in the audiophile world. 13.46V signals will produce almost square waves in typical amplifiers
You should list your special requirements either in your signature or in your profile at WBF. Otherwise your claims will be misinterpreted and misleading.
As I said already, regardless of load requirements, the Sonic Imagery opamps sound better than any IC or discrete opamps I've tried. On top of this, your not going to find an application that they can't handle. Which isn't the case for most other opamps.
People seem to think as long as your under the max rating then it's okay. Well I would prefer to drive an opamp at 0.5% load than 30-40%. There's a reason why several hundred thousand $ multi kilowatt class A amps sound good. It's not because people will be driving them to the max.
Last edited:
Rick Schultz, for the benefit of all people, could you please share some of your own DAC mods that we can do ourselves and improve our life with better sound?
Happy Thanksgiving Friday!
Happy Thanksgiving Friday!
Very few people have shared tweaks and mods like Ric:
http://tweakaudio.com/EVS-2/Schiit_mod.html
http://tweakaudio.com/EVS-2/Tweaks.html
plus all his posts online for years...
http://tweakaudio.com/EVS-2/Schiit_mod.html
http://tweakaudio.com/EVS-2/Tweaks.html
plus all his posts online for years...
Not related directly to improving DAC, more comms between PC and DAC.
My PC has a Paul Pang USB v2 card and I'm thinking of replacing the USB connectors with one of these:
as can be seen on the picture the connectors are integrated with magnetics for ESD protection and EMI filtering. Worthwhile trying or what do you think? Alternative to AQ JB and the likes??
Now ordered from Digikey to try out, they seem like the real deal for USB comms, at least worth a try
My PC has a Paul Pang USB v2 card and I'm thinking of replacing the USB connectors with one of these:
as can be seen on the picture the connectors are integrated with magnetics for ESD protection and EMI filtering. Worthwhile trying or what do you think? Alternative to AQ JB and the likes??
Now ordered from Digikey to try out, they seem like the real deal for USB comms, at least worth a try
Last edited:
Blizzard, I just wanted to pick your brain regarding DAC power supplies. I´ve read a lot of people mention the noticeable improvements in sound quality changing the power supply of your DAC can bring along and the superiority of LPS, has this also been your experience? Can you recommend a good power supply that doesn´t break the bank?
It all depends on the DAC. Things like this need to be assessed on a case to case basis.
To be honest, when it comes to DAC's of that caliber, you might be better off leaving as is. I think the best value modding DAC's can be had with sub $5000 units. However if you can find some pictures of the output stage and clock, I can see if there's some easy drop in upgrades.
(...)
The 2 easiest mods you can do are:
1: Master clocks
2: Discrete Opamp's
Depending on the DAC, even more mods are possible. If you have a Lampizator for example, several easy mods can be preformed that can result in huge performance upgrades for cheap.
If your among the crowd open minded enough to embark on this fruitful mission, let me know what you have, and I'll let you know what I think can be done cheaply and easily
Did you hear about the Stanford Research Systems PERF10 Rubidium Audio Clock and the cheaper DIY versions? http://www.soundstageultra.com/index.php/equipment-menu/610-stanford-research-systems-perf10-rubidium-audio-clock#most-read-equipment-reviews
This is highly suggestible for better performance. But Blizz is correct that some DAC's it's easier said than done, if at all.
However in regards to the whole topic, there is no better upgrade than very good power conditioning with PFC. Nothing else will make you listen more than that.
The only problem with external clocks are, no matter how low the jitter is, by the time the clock signal makes it to the chip it's clocking, the jitter is usually much higher than a higher jitter clock soldered to the board an inch from the chip.
I can not see why. I think that if you properly terminate your cables and optimize the layout a cable soldered half inch from the chip should not add jitter.
