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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
magfan
1,583 posts
 
Those prices for opamps are crazy high. Opamps are a commodity device and are typically sold (exaggeration alert) in bushell basket quantities.

The last 2134s I bought were about 2.50$ each.

http://search.digikey.com/scripts/DkSearch/dksus.dll?x=24&y=16&lang=en&site=us&KeyWords=opa2134
morningstaraudio's avatar
morningstaraudio
154 posts
 
I believe these are with the op-amps soldered into the Brown Dog adaptors.Well worth it IMHO .
Regards,
Bill
singleendedsingle
664 posts
 
Thanks for the list. Hopefully my friend buy a minimax plus version. opamp rolling will be fun.
magfan
1,583 posts
 
Looked at the BrownDog site and they are fine with 2134 pricing.
The adaptor? Solder in, from the look of it, so I don't know what that buys you. Plug in would be fine for swapping opamps. I guess I'm not current on what people are doing. I guess I don't know what the advantage is of soldering in an adaptor in which the part has to also be soldered in. The CMOY I built has a plug-in header so if I ever get the urge, I can swap opamps in seconds.
The single to dual adaptor makes sense.
sibelius
256 posts
 
Thanks for the info Doug. Just placed my order. I have an Ah!Tjoeb CD player in a second system and can attest that opamp rolling has made a difference over stock unit. For roughly $75 - $150 I think this is worth trying.

For now I have ordered the 2604's and 827's. Would be interested in feedback from folks who have tried and liked other combinations.

Love the fact that the EE DAC + allows swappable opamps. It greatly adds to its versatility. Agree 100% with Doug that the unit in SS mode with tube removed is the way to go.
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