Eastern Electric Minimax Tube Dac (32-bit dac) - Page 74

Quote:

Originally Posted by ecohifi 

It be interesting for you to compare the Burson and Dexa to the LME 49720/49860,  these will cost you a fraction of what the Dexa and I am interested in someone to compare them!

...or the 49990, which are better-sounding upgraded versions of the 49720/49860.

Quote:

Originally Posted by Shahrose 

 

...or the 49990, which are better-sounding upgraded versions of the 49720/49860.

The LME 49990 is used in the NAD M51,  they are good but I found them to be thin and lacking in definition on the low end, they are also more critical in set up and tend to be unstable. This is why I have never tried it in the EE.  The 49720 are robust in stability and have better low end definition,

Quote:

Originally Posted by ecohifi 

The LME 49990 is used in the NAD M51,  they are good but I found them to be thin and lacking in definition on the low end, they are also more critical in set up and tend to be unstable. This is why I have never tried it in the EE.  The 49720 are robust in stability and have better low end definition,

I've tested all extensively in the Minimax. The 49990 just sound like airier, more detailed versions of the 49720. They're all stable, and none of them are thin-sounding to me. In fact, tone is very similar among all of them. Technical performance is the main difference.

Quote:

Originally Posted by Shahrose 

 

I've tested all extensively in the Minimax. The 49990 just sound like airier, more detailed versions of the 49720. They're all stable, and none of them are thin-sounding to me. In fact, tone is very similar among all of them. Technical performance is the main difference.

Yeeep, thats what I did and thats what I thought, then you go back to the 49720 and find out the presentation exceeds the 49990 especially in base definition.  In the M51 there are areas where the 49990 have polystyrene caps for RF and they are not for the audio path!  If its stable in your EE then leave it, dont change.  If you want airier and detail, try the ADA 4627-1brz, this chip is better than the 49990 IMO but its expensive! 

Quote:

Originally Posted by ecohifi 

Yeeep, thats what I did and thats what I thought, then you go back to the 49720 and find out the presentation exceeds the 49990 especially in base definition.  In the M51 there are areas where the 49990 have polystyrene caps for RF and they are not for the audio path!  If its stable in your EE then leave it, dont change.  If you want airier and detail, try the ADA 4627-1brz, this chip is better than the 49990 IMO but its expensive! 

In the M51 or Minimax? I'm only referring to the latter for the purposes of this thread. I know atleast 8-9 people who swapped between both opamps and all of them preferred the 49990 (incl me). Check also on audiocircle and other forums which have a larger following of the EE DAC than Head-Fi. They all say the same.

I didn't get a chance to try the 4627 unfortunately. After going through something like 15 different opamps (and many more combinations) I kept coming back to the 49990, so I just left it there after a while and stopped experimenting. For me, the two things that made the biggest improvements in the DAC were those opamps, and the Tunsgram or Amperex E80CC tubes.

The M51 comes stock standard with 49990 and a TL082 for RCA buffer. 

Im going to try the AD823A, LME 49860 and the LME 49880 next...  But not in the EE mini max!

That's cool, but how the 49990 performs in the M51 has nothing to do with how it sounds in the EE Minimax DAC. This thread is not about the NAD M51. They each have different specs and requirements.

I'd like to know why most of these fet opamps, especially when mounted on Brown Dog adapters for dual application in U1/U2, get so darn hot. Doesn't that indicate oscillation? Non of the bi-polars or discretes that I've tried do this.

Quote:

Originally Posted by Turn&cough 

I'd like to know why most of these fet opamps, especially when mounted on Brown Dog adapters for dual application in U1/U2, get so darn hot. Doesn't that indicate oscillation? Non of the bi-polars or discretes that I've tried do this.

Which ones have you tried, not all go hot in the EE!

Questkon, if the  LME49990 duals go into the U1/U2 as mentioned above, do you also have to have single LME49990 opamps  mounted on the U3/U4 slots?

Would a combination of two different types of opamps in the two different sets of U1/U2  and U3/U4 work, but create a different sound?

thanks.

Quote:

Originally Posted by Carlsan 

Questkon, if the  LME49990 duals go into the U1/U2 as mentioned above, do you also have to have single LME49990 opamps  mounted on the U3/U4 slots?

Would a combination of two different types of opamps in the two different sets of U1/U2  and U3/U4 work, but create a different sound?

 

thanks.

No you dont have to change U3/U4.  Once you have implemented U1/U2 with LME 49990 you will be tempted to change U3/U4.  As any modern opamp is better than the stock

Does anyone know if the OPA637 will work in the output stage?  I am using an OPA627 currently and am curious about the potential for HF extension of the the OPA637 but not sure if the opamp would be stable in this application.

I guess I'll try my luck at an opamp question.

Why Cimarron's "Brown Dog Adapters?"  Is there any reason to avoid cheaper options like those listed on eBay?

I want to opamp tweak my "Plus".  If I go the Cimarron route, it gets pretty expensive.

If I go the cheaper route, I can get tons of combinations which is appealing.

Any thoughts?

Before you go and spend a fortune on Brown Dogs or discrete opamps you could give the LME49710/20 single/dual combo a try. They're cheap, don't require adapters and available from Digikey. IMHO they are in the same ballpark as the well liked LM49990s which are only available in SOIC form.

Quote:

Originally Posted by Turn&cough 

Before you go and spend a fortune on Brown Dogs or discrete opamps you could give the LME49710/20 single/dual combo a try. They're cheap, don't require adapters and available from Digikey. IMHO they are in the same ballpark as the well liked LM49990s which are only available in SOIC form.

Thank you, I will look into that. I have already spent a lot of money on opamps. I have tried Burson and DEXA in my Plus. I'll look into Digitech.

Now I want to get some singles to compliment. I was just wondering if there is any benefit buying from Cimarron? I assume they are better quality, but does it translate to better sound?

Regarding eBay. I guess the main issue is avoiding fakes?