turn&cough said:

I can't help but wonder why the EE designer chose the 5232 and 5234 op amps. Maybe there is a good reason other than cost. After all most op amps are relatively inexpensive. Maybe some of us(me) didn't take the time to do an objective comparison assuming that all these other audiophile op amps would trounce the lowly NXP ones. Maybe...
 

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shahrose said:

 
I remember reading about this on other forums (Audiocircle, audionervosa etc) and Alex (or Bill) said the stock opamps were stable, cheap, and had pretty good SQ. Some other opamps may have better specs, but they are not as stable in this circuit/design.
 
I've chosen to live with the 4xLME49990 as I feel they are some of the few opamps that beat the stock in SQ.

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mrscary said:

shahrose said:

 
I remember reading about this on other forums (Audiocircle, audionervosa etc) and Alex (or Bill) said the stock opamps were stable, cheap, and had pretty good SQ. Some other opamps may have better specs, but they are not as stable in this circuit/design.
 
I've chosen to live with the 4xLME49990 as I feel they are some of the few opamps that beat the stock in SQ.

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Stability is not an issue as long as you read the specs on the manufacturers site for a given opamp .. The NE's dont add anything or subtract this is a known quality they are just neutral
Yeah the 49990's sound good they are a bit to bright in my system but they sounded great until I went with a couple silver connections.. I have dual 797's coming in in the next couple weeks it will be interesting to see how they sound in U1 and U2 they sound
great in other equipment interesting test.

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silverrs8 said:

After reading all the raving reviews I decided to order a Minimax DAC and have no regrets. What a great device. I was also intrigued by the op-amp and tube-rolling thing. I'm new into those worlds and just ordered a cheap tube first (Mullard standard series) just to hear what that would do to the sound before going for the more high-end ones. Well, the sound was crap. Conclusion: tubes can make a huge difference. Now I'm trying to get my hands on a Siemens Silver Plate.
 
Also have swapped the standard op-amps for the LME49710/20 ones. Those are a little bit brighter in sound but I was missing the warm mids so back to the factory op-amps.
 
I like the factory SQ but would like it to be just a little more bright but without changing the rest. What is best to do? Role the tube (can you advise which was would be good to try) or roll the op-amps (for which ones?).
 
Also I read somewhere that the stock EE tube is a Shuguang 12AU7 tube. Does anybody know which type to be exact?
 
Great work and great forum this one. Learning a lot here already....

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mrscary said:

Quote:

shahrose said:

I remember reading about this on other forums (Audiocircle, audionervosa etc) and Alex (or Bill) said the stock opamps were stable, cheap, and had pretty good SQ. Some other opamps may have better specs, but they are not as stable in this circuit/design.
 
I've chosen to live with the 4xLME49990 as I feel they are some of the few opamps that beat the stock in SQ.

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Yeah the 49990's sound good they are a bit to bright in my system but they sounded great until I went with a couple silver connections.. I have dual 797's coming in in the next couple weeks it will be interesting to see how they sound in U1 and U2 they sound
great in other equipment interesting test.

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9pintube said:

I also happen to like the sound (in my system) using all 49990 op-amps.  I, 1st tried  mixing the Dual 49990 with the single 797's and that produced a lot deeper sound stage with the whole Dac improving over the stock Op-amps, which sounded flat (no depth)...  Then my partner in crime, Bubu1 suggested switching to all 49990's and we both agreed they seem to match (gel) better together so with his help and opinion I ordered the Dual AD797BRZ  Op-amps to see how they would sound with their single 797's along side..They should be here Monday..... As far as the Tube swapping I like the NOS Telefunken 12au7....Sound...   But, a big surprise that Tom and I noticed is that my JKenny Hi Face has BNC outs so a buddy of mine let me try a Transparent Audio $$$ BNC to BNC into the EE Mini and it seemed quieter to us (or a Blacker back ground as they say).....  I haven't tried swapping the fuse for the silver ceramic Jobie! ....This has got to be one of the best Dacs out there for around a grand,( with all the different sets of Op-Amps and tubes, etc.etc.) I like having all of the options we have to play with to get "IT" to match our systems.....But I must say Bubu1's Headrooms "Big Dog" Dac with the upgraded power supply still sounds a little more spacious and even throws a deeper and wider sound stage and that's using all the same equipment, in my system..... Thanks for all the great advice/help Shahrose and MrScary, any other mods I should try.......That have pleased you two!  I've been a "vinyl only guy" in my main system but with Tom's help taking me to the "dark side", with the  (high res downloads and  the JKenny Hi-Face teamed up with this Dac) The tunes are really close to the Lps without the surface noise let alone the convenience of using the I phones remote AP.......

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morningstar said:

Hi Guys,
 
 God, this is so subjective, The Siemens silver plate 12au7 is definitely one of my top 3 favorites. Would I recommend this with SS amps? probably not. I say that being a tube guy. This is a very neutral/natural tube. It has extension up the yin yang.It could be to neutral for some systems.
If you are using SS amps and have revealing tone coming thru right now and are looking for a warmer tone to soften the relentless detail of SS, you really have to be the judge here, if it is just a tad to analytical ,then on one extreme the old RCA black plate D getter version from the 1950's era might be your ticket to the tone you seek.This tube does wood bodied instruments ,female vocals, skins of drums as well as any I've heard.Keep in mind though it tends to be the one of those that will have you just staying up late at night listening saying "that sounds wonderful" but it is a full bodied warmer presentation of the spectrum.
 Back to the Siemens Silver plate,natural and a complete revelation into what is in the recording, plus it has a wonderful taut bottom end with an extension on the highs that is so superior to any others that air, tinkling of cymbals,and just the clean presentation may make you wonder why any other tube .
Evaluate your systems tone, what would you change? The tone you seek may be such a simple change in tube.
 My expertise is not in op-amp rolling, I'll leave that to those in the know.
 
Side note: we have stopped selling the original DAC. A Mk2 version will be available in about a month. Here are the features.I just didn't want folks PO'd at me that I sell them a DAC and a month later an updated version is available.The cost will be $1050-1100 depending upon my shipping cost. Please keep in mind that just the price of metals are up about 30% across the board . We also have eliminated the volume control on this MK2 version. 
[size=16.0pt]1. Sabre ES9018 DAC chip[/size]
[size=16.0pt]2. A Sync USB 32/192[/size]
[size=16.0pt]3. Dual power transformers separate digital and analog[/size]
[size=16.0pt]4. improved tube output stage[/size]
[size=16.0pt]5. improved PSU[/size]
[size=16.0pt]6. improved signal input section with high frequency relays/resistors module[/size]
[size=16.0pt]7. Tube/SS outputs selectable[/size]
[size=16.0pt]8. Socketed output op amps[/size]
9. improved S/N level
 
 I know that Alex Yeung has had the prototype floating around  between his friends Vincent/Vintage Sounds in HK plus those who regularly hang out there and his best friend/man at  his wedding Tim/President who runs the HK Audio Tube Club and both are taken back by the significant upgrade in the sound quality from the original.
 
 I follow a lot of the threads here but because of being the distributor of EE I have to very careful of not crossing a line. I hope this isn't.
 
 May Love Always Abide,
Bill
  

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9pintube said:

I also happen to like the sound (in my system) using all 49990 op-amps.  I, 1st tried  mixing the Dual 49990 with the single 797's and that produced a lot deeper sound stage with the whole Dac improving over the stock Op-amps, which sounded flat (no depth)...  Then my partner in crime, Bubu1 suggested switching to all 49990's and we both agreed they seem to match (gel) better together so with his help and opinion I ordered the Dual AD797BRZ  Op-amps to see how they would sound with their single 797's along side..They should be here Monday..... As far as the Tube swapping I like the NOS Telefunken 12au7....Sound...   But, a big surprise that Tom and I noticed is that my JKenny Hi Face has BNC outs so a buddy of mine let me try a Transparent Audio $$$ BNC to BNC into the EE Mini and it seemed quieter to us (or a Blacker back ground as they say).....  I haven't tried swapping the fuse for the silver ceramic Jobie! ....This has got to be one of the best Dacs out there for around a grand,( with all the different sets of Op-Amps and tubes, etc.etc.) I like having all of the options we have to play with to get "IT" to match our systems.....But I must say Bubu1's Headrooms "Big Dog" Dac with the upgraded power supply still sounds a little more spacious and even throws a deeper and wider sound stage and that's using all the same equipment, in my system..... Thanks for all the great advice/help Shahrose and MrScary, any other mods I should try.......That have pleased you two!  I've been a "vinyl only guy" in my main system but with Tom's help taking me to the "dark side", with the  (high res downloads and  the JKenny Hi-Face teamed up with this Dac) The tunes are really close to the Lps without the surface noise let alone the convenience of using the I phones remote AP.......

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mrscary said:

Thanks Bill for the update , doesn't sound like a whole lot of upgrade unless you seek the USB 32/192 for the cost increase. I think at 750.00 the Minimax is very competitive but at 1100.00 I personally will start comparing and looking elsewhere.
 

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mrscary said:

If you are looking to for just a little brighter sound then the psvave or siemens is the way to go. if you like the siemens great if not order one 12au7 psvane from Grant fidelity,its the same tube that Boulder Cable uses to do their level 1 mods that can be done to the Minimax.    The stock opamps are meant to be neutral the NE's have this as a known quality. Any other opamp colors the sound so it takes alot of swapping to find the right combo. I'm still swapping opamps and waiting on dual AD797's for U1 and U2 as I want to warm up my system just a tad.

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silverrs8 said:

Thanks for the advise. I have just ordered the Shuguang psvane 12au7 Reference T-serie. Curious on whether it will be an improvement.
 

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mrscary said:

Let me know how the dual 797 sounds in U1 and U2 I have some ordered but ordered from overseas and it will take a couple weeks to get here I am very interested if the dual 797's will warm up the system a bit... sounds like you have it covered

You can always get a silver fuse that brightens the sound just a tad believe it or not.. but right now they are scarce Boulder Cable used to sell them but they cannot get stock..
 
 

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shahrose said:

Ah maybe you're the guy Tom was telling me about. Glad you're enjoying the EE DAC. Check my profile for the list of mods that I had a popular DIY'er perform on my DAC. Definitely takes it up to a whole different level (doubled the price of the DAC though).

 

 
Those are very significant upgrades IMO. The PSU (along with dual trafos) and output stages are some of the most important components of a DAC. Plus, removing the Alps volume control and associated wiring was already a pretty big upgrade in the original, so the MK2 is going to sound awesome I bet. If my EE wasn't heavily modded, I'd go for the new one.

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9pintube said:

I'll keep you posted...... I'm with you on the new Dac (unless we could use the extra Op-amps, tubes etc.etc.) that we bought for the $750 EE Mini Dac... IMO they're now stepping into a price range that will have some stiffer competition!    I'd get the Headroom "Big Dog" Dac because I've heard it in my system, as I said in my post above...... But MrScary, I'll let you know when I install the new dual 797 chips... and stick the single 797's back in...Thanks for the FUSE info.......I'm fine with the stock one unless I can find the 12 buck one......
 
 

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