Listing of Opamps for EE Minimax DAC Plus


Phil from Cimmaron Technology sent me a list of approved Opamps for
respective positions on the board of the EE Minimax DAC Plus; prices
include the Brown Dog Adapters provided by Cimmaron. I have been using
in the U1/U2 position the OPA2604 and in the U6/U7 position the OPA827.
I have not Opamp rolled this unit much, as I have been busied with other
components for review. I attest that the DAC Plus in SS output with the
tube removed and these opamps is sensational.

(NOTE CAREFULLY the warning at the bottom NOT to use the AD 8620 in the U1/U2 positions!) Also note that the positioning of the opamps/adapter is always with the small square solder point on the topside of the Opamp at the upper right hand when the unit is facing the installer. Finally, it is recommended that an opamp extraction tool and an anti-static device be used when removing/installing Opamps.

Is it "worth it"? YES! YES! YES! :)

RECOMMENDATIONS OF OPAMPS FROM CIMMARON TECHNOLOGY:
For U1/U2
Single-channel op-amps mounted on the 020302 SO8-to-DIP8 single-to-dual
channel adapter:
qty 2 each required

020302-OPA627 $48.00 x 2 = $96.00
020302-OPA827 $38.00 x 2 = $76.00
020302-AD797B $48.00 x 2 = $96.00

. . . also for U1/U2
Dual-channel op-amps mounted on the 970601A SO8-to-DIP8 adapter
qty 2 each required

970601A-AD8620 $23.00 x 2 = $46.00
970601A-OPA2604 $13.00 x 2 = $26.00
970601A-OPA2134 $10.00 x 2 = $20.00

For U6/U7
Single-channel op-amps mounted on the 970601A SO8-to-DIP8 adapter
qty 2 each required

970601A-OPA627 $28.00 x 2 = $56.00
970601A-OPA827 $23.00 x 2 = $46.00
970601A-AD797B $23.00 x 2 = $46.00

The AD 8620 should not be used in the DAC PLUS.
"On some forum there was a suggestion to use the AD8620. for positions U1
and U2. While this is a dual op-amp, it is only rated to use up to
plus/minus 13 volts. The circuit in the EE Mini Max DAC and DAC Plus is
plus/minus 15 volts."
douglas_schroeder

Showing 12 responses by morningstaraudio

I believe these are with the op-amps soldered into the Brown Dog adaptors.Well worth it IMHO .
Regards,
Bill
Magfan,
I believe some of the op-amps are to small to just plug into the EE DAC PLUS, that is why the need for the Brown Dog adaptors.So you do not have to solder the smaller op-amps into the MiniMax.

No, you then do NOT have to solder the BD adaptors into the sockets. You should never put your soldering in any of the components in the DAC PLUS. Very sensitive inside the DAC.
That is the reason for the BD adaptors so you don't have to solder.

Thanks,
Bill
I also took shipment today of the 2604's and 827's on the Brown Dog adaptors.
A truly significant upgrade to the stock op-amps in sound. Very organic,more meat on the bone kind of tone. Punchier bottom end with a wonderful midrange.
I'll probably be offering the DAC PLUS with these pre-installed by me as it won't void the warranty that way.

Don't ask me why it took me so long to try.
Thanks to all that have contributed.
Warmest Regards,
Bill
Davemm,
I bought some extra 2604's and 827's and I Have the DAC's in stock so give me a call.
Absolutely loving the OPA2604 duals with the OPA827 singles on the Brown Dog adaptors. Really fleshed out the midrange and added punch to the bottom end.
I wrote Alex a week or so ago regarding the use of the Burson's.
Here is his reply.

Hi Bill,

Sorry for my tardy reply, I was away. I checked the Burson web site, it said clearly
that their dual one can replace the NE 5532 and the single one can replace the NE
5534. So they will work just fine with the DAC and The Plus.

Thanks.

Best regards,

Alex
Skomak,

I was concerned also and wrote Alex again just to double check. His reply;

Hi Bill,

The DAC Plus has enough current supply for four Burson opamps.

Hope the above helps.

Thanks.

Best regards,

Alex
Only been playing them for a day, but immediately noticed going thru the SS output with tube removed and the dual OPA2604's still in the U1/U2 dual position with the single Dexa's in the U6/U7. Lovely smooth presentation, totally agree with Sibelius on the analog tone to this combo.
This morning installed the dual Dexa's in U1/U2 position and running that at the moment with a Siemens silver-plate thru the tube output.Really haven't had time to critical listen as now just doing some background music to burn in a bit.
Thanks to all of you who recommended these.
Later,
Bill
Yes, they do fit under the cover.
You have to make sure just to put them in correctly with the half moon circle cut out on the base of the Dexa'a always on the right hand side while looking at the front of the DAC PLUS.
Roy,Mrtennis
I can't explain it any better then what I told you over the phone yesterday.
The Burson's do not fit under the top cover of the DAC. I do not recommend using as they also draw a lot of current.

Very much so the op-amps make a difference. I still like the OPA2604 duals and the OPA827 singles.
Having lived with the DEXA Discrete op-amps for about 3 weeks now, they really do seem to be the one's to beat. I highly recommend for the tube output the Philips E80CC pinched waist D getter version as a substitute for the 12au7. Although this tubes is twice the length and you won't be able to put the tube shield in place anymore , and being that this isn't a direct substitute for the 12AU7 as it draws twice as much heater current, Alex Yeung the designer says it is ok to use. This tube with the Dexa's is fantastic!