Thanks, Siva.
I shall not run at max amplitude all the time in the interest of domestic harmony, neighbourly harmony, and longer life of amp:lol:
Group Buy: Mauro Penasa MyRef Rev C kit
- Thread starter linuxguru
- Start date
- Status
Thanks, Siva.
I shall not run at max amplitude all the time in the interest of domestic harmony, neighbourly harmony, and longer life of amp:lol:
My 3886 doesn't have metal tab. It's plastic (or whatever is the black thing) all around.
Audiodoc
Well-Known Member
So it is a LM3886TF and you don't need to worry about any mica washers just use some heat sink compound though.
Yeah, already have a couple of tubes of the compound.
A work-in-progress shot here: Flickr: joshua.singson's Photostream
Most caps, diodes, and transistors populated.
Resistors and active devices to be filled in, cablings to be done.
Joshua
Most caps, diodes, and transistors populated.
Resistors and active devices to be filled in, cablings to be done.
Joshua
sachu888
Well-Known Member
Hi,
It looks good Joshua.Did you able to source any enclosure for this?
Regards,
Sachin
It looks good Joshua.Did you able to source any enclosure for this?
Regards,
Sachin
Cab is still pending. I went to Dinrack last Sat but couldn't get something readymade, so need to go to again on Sat and get a customised cabinet (customised as in dimension). I do like their industrial looks though some folks don't favour them much.
Joshua
Anil kumar
Well-Known Member
Hi Joshua & Sachin, i am in the process of completing the LM3886 project soon, here is my cabinet design.
Anil
Anil
Audiodoc
Well-Known Member
Really loved your DIY effort on the enclosure. Are there any chances of anodizing the cabinet before you assemble it. It would look better and prevent alterations in metal finish from the elements.
You could also incorporate one more finishing touch to make it look even better. The front panel has 4 screws which are protruding out, get each of the hole drill around 2 mm deep with a diameter slightly larger that the screw head so you can screw them down through the drilled hole. You can also try brushing the front panel from left to right, after going through google, for similar DIY brushed aluminum finishes.
You could also incorporate one more finishing touch to make it look even better. The front panel has 4 screws which are protruding out, get each of the hole drill around 2 mm deep with a diameter slightly larger that the screw head so you can screw them down through the drilled hole. You can also try brushing the front panel from left to right, after going through google, for similar DIY brushed aluminum finishes.
Last edited:
sachu888
Well-Known Member
Hi Joshua & Sachin, i am in the process of completing the LM3886 project soon, here is my cabinet design.
Anil
Hi Sir,
Your enclosure is too good.I read your LM3886 thread.It would be great if you can offer some enclosure for interested members.
Regards,
Sachin
Anil kumar
Well-Known Member
Thanks Audiodoc & Sachin, anodizing will be done after mock-up, that will happen very soon. I am countersinking the front 4 screws, front panel will have brushed aluminum finish (planning for champagne gold finish)
Regards,
Anil
Regards,
Anil
Last edited:
keith_correa
Well-Known Member
Actually, IMO, they look better without the countersinking. Industrial!
Hi Anil - great-looking industro-tech design. BTW, the 8Audio cabinet used by Audiodoc (and also the same as I have ordered), looks very similar conceptually, except
that it does not have finned heatsinks on the sides, just extruded panels.
A quick update on op-amps for the MyRef Rev E: One of the side-benefits of the Rev E compensation modification is that there is some flexibility for rolling opamps other than the stock LM318. Here are my preliminary tests with a few opamps.
1. Burr-Brown OPA627AU (the flagship Burr-Brown single-opamp, which still holds its own after 15+ years against the latest Si-Ge offerings from TI/Burr-Brown like the OPA211/1611 and the OPA827)
This is a SOIC-8 internally-compensated single opamp, mounted on a Sjostrom Audio ADP05 DIP-8 adapter (similar to a Brown-dog adapter) and plugged into the DIP8 socket of the MyRef Rev E.
Audible impressions: Excellent micro-detail and dynamics, slightly edgier than the stock LM318, and has the typical laid-back Burr-Brown sound. Perfect for jazz instrumental, strings, piano, etc. Unconditionally stable, but the LM3886 chipamp runs warmer than with the LM318.
2. NatSemi LME49710HA (formerly the flagship NatSemi single-opamp, now overtaken by the SOIC-8 LME49990).
This is the TO99 metal-can version, reputedly the best-sounding of the LMe497xx series. I formed the leads slightly, plugged it into a spare DIP-8 socket, and then plugged the combination into the DIP-8 socket of the MyRef Rev E.
Audible Impressions: Astonishing micro-detail, very dark and quiet. It would have been my favourite, except for the fact that it's unstable in the MyRef Rev E, and SPiKe protection starts kicking in after a few minutes. Maybe this can be fixed with some compensation mods, but then it will no longer be a Rev E - we'll see.
3. LF-01 discrete-hybrid opamp.
This is a SOIC-8 LM318 with an additional Class-A discrete BJT output stage, all mounted on a small DIP-8 module that fits directly in the DIP-8 socket of the MyRef.
Audible Impressions: Very smooth, full-bodied and non-fatiguing, but does not reach the darkness of the LME49710 or the detailed, laid-back presentation of the OPA627AU. Vocals sound exceptional, and just about all genres of music sound fine.
Not tested:
LT1028 (the flagship Linear Tech single opamp) and the AD797B (the flagship Analog Devices single-opamp). The LT1028 is unstable in simulation, so I'm certain it won't be stable in a real MyRef Rev E. The AD797B is unobtainium for now, but will probably be as good or better than the OPA627AU.
Conclusions: The LF01 and the plain LM318 are still the best tradeoffs overall in the MyRef Rev E, because of their unconditional stability and compensation optimized for the MyRef. The Burr-Brown OPA627AU is a good, if expensive, alternative.
1. Burr-Brown OPA627AU (the flagship Burr-Brown single-opamp, which still holds its own after 15+ years against the latest Si-Ge offerings from TI/Burr-Brown like the OPA211/1611 and the OPA827)
This is a SOIC-8 internally-compensated single opamp, mounted on a Sjostrom Audio ADP05 DIP-8 adapter (similar to a Brown-dog adapter) and plugged into the DIP8 socket of the MyRef Rev E.
Audible impressions: Excellent micro-detail and dynamics, slightly edgier than the stock LM318, and has the typical laid-back Burr-Brown sound. Perfect for jazz instrumental, strings, piano, etc. Unconditionally stable, but the LM3886 chipamp runs warmer than with the LM318.
2. NatSemi LME49710HA (formerly the flagship NatSemi single-opamp, now overtaken by the SOIC-8 LME49990).
This is the TO99 metal-can version, reputedly the best-sounding of the LMe497xx series. I formed the leads slightly, plugged it into a spare DIP-8 socket, and then plugged the combination into the DIP-8 socket of the MyRef Rev E.
Audible Impressions: Astonishing micro-detail, very dark and quiet. It would have been my favourite, except for the fact that it's unstable in the MyRef Rev E, and SPiKe protection starts kicking in after a few minutes. Maybe this can be fixed with some compensation mods, but then it will no longer be a Rev E - we'll see.
3. LF-01 discrete-hybrid opamp.
This is a SOIC-8 LM318 with an additional Class-A discrete BJT output stage, all mounted on a small DIP-8 module that fits directly in the DIP-8 socket of the MyRef.
Audible Impressions: Very smooth, full-bodied and non-fatiguing, but does not reach the darkness of the LME49710 or the detailed, laid-back presentation of the OPA627AU. Vocals sound exceptional, and just about all genres of music sound fine.
Not tested:
LT1028 (the flagship Linear Tech single opamp) and the AD797B (the flagship Analog Devices single-opamp). The LT1028 is unstable in simulation, so I'm certain it won't be stable in a real MyRef Rev E. The AD797B is unobtainium for now, but will probably be as good or better than the OPA627AU.
Conclusions: The LF01 and the plain LM318 are still the best tradeoffs overall in the MyRef Rev E, because of their unconditional stability and compensation optimized for the MyRef. The Burr-Brown OPA627AU is a good, if expensive, alternative.
Last edited:
Update 2:
Flickr: joshua.singson's Photostream
Pending: get suitable heat sink (the one I bought are not suitable), soldering op amp, soldering DC de-coupling cap, buying wires and connecting them, thorough visual check, power on, testing, cabinetry.
Flickr: joshua.singson's Photostream
Pending: get suitable heat sink (the one I bought are not suitable), soldering op amp, soldering DC de-coupling cap, buying wires and connecting them, thorough visual check, power on, testing, cabinetry.
Completed my amp more than a year back and been listening to it off-and-on in a perpetual breadboard state. Finally last week decide to " DEXA" box it pending the final professional look whenever it happens.
The listening impressions are very good - though I do not understand most of the terms used here for my genres - jazz - smooth and instrumental, and country it is doing good duty and I prefer it over my old Arcam workhorse. I use it with my Fostex BLH floor standers.
I am controlling the volume from my cd source volume control. There is a slight
hum at max volume, this does not seem to change with wiring changes and
grounding variations etc. Need to find time to investigate it further.
Next steps - need to change all connectors with better jacks etc. - Get to the bottom of the hum issue and then box it.....Oh well it is going to take some time.
Anyhow I must thank Linuxguru for making this happen for me as I got back into DIY after more than 20 years....good fun...:yahoo:
Pic here...http://www.hifivision.com/diy/21733-norge-1000s-modded-avatar-lands-5.html#post306716
The listening impressions are very good - though I do not understand most of the terms used here for my genres - jazz - smooth and instrumental, and country it is doing good duty and I prefer it over my old Arcam workhorse. I use it with my Fostex BLH floor standers.
I am controlling the volume from my cd source volume control. There is a slight
hum at max volume, this does not seem to change with wiring changes and
grounding variations etc. Need to find time to investigate it further.
Next steps - need to change all connectors with better jacks etc. - Get to the bottom of the hum issue and then box it.....Oh well it is going to take some time.
Anyhow I must thank Linuxguru for making this happen for me as I got back into DIY after more than 20 years....good fun...:yahoo:
Pic here...http://www.hifivision.com/diy/21733-norge-1000s-modded-avatar-lands-5.html#post306716
Last edited:
Audiodoc
Well-Known Member
@jls I am a step ahead on you with the linuxgurus My Ref. Everthing soldered, Heatsinks and Toroid ready. Waiting for enclosure.
@gopip. Same here started DIY after 10 long years though with the EHHA build. Have made 6 projects in the last 2 months now.
@gopip. Same here started DIY after 10 long years though with the EHHA build. Have made 6 projects in the last 2 months now.
Last edited:
Suggestion: Leave the opamp socketed - it will allow easy rolling of alternatives, including the LF-01, in the future. You can also choose between the NatSemi and TI LM318, which have subtle differences in sonics.
Found time after 2 long weeks to order cabinet from Dinrack. It will be a 2U (meaning 3.5 inches height outer dimension), 19 inch wide, and the depth will be 200mm (a bit less than 8 inch). This will be a raw cabinet. I will manually cut all holes myself. Delivery on coming Wed evening.
Also ordered heatsink, 180mm long, 3.5 inch tall, 20mm fin extrusion. May get it next Sat.
Bought PTFE (teflon) insulated 15AWG red, black and white wires for power and signal cabling. Didn't buy termination clips as they were available in packets of 500 pieces only!
@linuxguru: opamp socket used. Opamp rolling - that's something new I haven't rolled even the tubes in my pre or power amps. So I'm not sure if I'll have the energy for opamp rolling.
Also ordered heatsink, 180mm long, 3.5 inch tall, 20mm fin extrusion. May get it next Sat.
Bought PTFE (teflon) insulated 15AWG red, black and white wires for power and signal cabling. Didn't buy termination clips as they were available in packets of 500 pieces only!
@linuxguru: opamp socket used. Opamp rolling - that's something new
I haven't rolled even the tubes in my pre or power amps. So I'm not sure if I'll have the energy for opamp rolling.
Audiodoc
Well-Known Member
Do share the pictures and price of the dinrack cabinet. Mine has also arrived unfortunately the toroid was a few mm taller. Am building the most compact My Ref F.
- Status
Wharfedale Linton Heritage Speakers in Walnut finish at a Special Offer Price. BUY now before the price increase.
