Hi,
I need a little help from some knowledgeable builders of this dac:
I have the dac boards that have the soic-8 (smd) pads for the opamp, and I would like to install an opa1655. If I was not planning on opamp rolling, would I experience any difference in sound quality by soldering an 1655DR directly on the pads vs an dip type 1655 in an adapter.
I am getting a parts list going, so would like to use the best form of opa 1655. I have no problem using an dip adapter if need be for the 1655. Also smd was cheaper than dip if I remember correctly.
Thanks for the help,
MM
I need a little help from some knowledgeable builders of this dac:
I have the dac boards that have the soic-8 (smd) pads for the opamp, and I would like to install an opa1655. If I was not planning on opamp rolling, would I experience any difference in sound quality by soldering an 1655DR directly on the pads vs an dip type 1655 in an adapter.
I am getting a parts list going, so would like to use the best form of opa 1655. I have no problem using an dip adapter if need be for the 1655. Also smd was cheaper than dip if I remember correctly.
Thanks for the help,
MM
Thanks zoom. I have 3 smd boards and 1 tht board, so lots of amp rolling possibilities. Just want to get one done for now with the 1655, hence the reaching out for knowledge. It looks like the 1655 leg type is not even listed on parts websites, only smd.
If i were you, I would just do up the THT board, and i would be able to use DIP or SMD ( with adapter board of course).
After playing a while and i am very certain OPA1655 is the final op amp i want to be on the board, i would do the board with smd pads and solder the op amp directly. I think the OPA1656 and 1655 comes in smd packages only.
After playing a while and i am very certain OPA1655 is the final op amp i want to be on the board, i would do the board with smd pads and solder the op amp directly. I think the OPA1656 and 1655 comes in smd packages only.
I built the SMD pad MiroDac board a while back and never played with opamps again, OPA1655 was the one for me….. But then AD811 happened 😂.
Use the through hole board for discrete I/V experimentation
.
Use the through hole board for discrete I/V experimentation
.
Thanks to all for the valuable knowledge and opinions. Medical issues and life in general has meant limited time for working on this hobby. I really don't have the knowledge, time or the patience required to search for the "holy grail" of sound quality. So my first miro dac will be the smd board with the opa1655DR opamp. I will listen and be happy.
The other 2 smd boards and the thru hole board will be used for a minimum amount of opamp rolling and also playing around with the Cen IV and discrete IV ala AD844 which I have in my inventory.
@Vunce, by " discrete IV experimentation" are you saying you would use the thru hole for discrete on board opamps like Burson, Sparkos, etc or are you referring to using the thru hole for off board experimentation like the Cen IV. Would not the smd dac boards lend themselves for use with off board experiments and the thru hole to onboard experimentation ? Just trying to get clarity in my mind. 🙂
Regards,
MM
The other 2 smd boards and the thru hole board will be used for a minimum amount of opamp rolling and also playing around with the Cen IV and discrete IV ala AD844 which I have in my inventory.
@Vunce, by " discrete IV experimentation" are you saying you would use the thru hole for discrete on board opamps like Burson, Sparkos, etc or are you referring to using the thru hole for off board experimentation like the Cen IV. Would not the smd dac boards lend themselves for use with off board experiments and the thru hole to onboard experimentation ? Just trying to get clarity in my mind. 🙂
Regards,
MM
Hi Myles,
Build the SMD board with OPA1655 installed and use that as your MiroDac reference, if you didn’t build any other version you would be totally pleased.
Use the through hole board to play around with opamps and off-board I/V circuits.
The crop of discrete opamps like Burson and Sparkos do sound very good, but IMO are no fun. Buy them, plug them in and done…..next up….
I need a bit more bonding time with the project
.
Build the SMD board with OPA1655 installed and use that as your MiroDac reference, if you didn’t build any other version you would be totally pleased.
Use the through hole board to play around with opamps and off-board I/V circuits.
The crop of discrete opamps like Burson and Sparkos do sound very good, but IMO are no fun. Buy them, plug them in and done…..next up….
I need a bit more bonding time with the project
.
Thanks Vunce,
I will probably get some dip to soic adapters so I can play with some on board opamps for the other 2 smd boards, and use the thru hole for the off board IV circuits as you suggest. Burson and Sparkos add up $$ quickly, will look at my list of opamps (saved from thread researching) to see what other builders have used / liked at a lower cost.
Best regards,
MM
I will probably get some dip to soic adapters so I can play with some on board opamps for the other 2 smd boards, and use the thru hole for the off board IV circuits as you suggest. Burson and Sparkos add up $$ quickly, will look at my list of opamps (saved from thread researching) to see what other builders have used / liked at a lower cost.
Best regards,
MM
Nah, never had a problem with DIP8 opamps in sockets, the AD811 is too expensive to solder, LOL!
Hello All,
Gathering parts and have a general question. Concerning R8,R9, what is a common output voltage from the DAC for the input to a preamp ? Is the 1k4 resistor enough (approx 1V rms) or does it need to be around 2V rms.
@ Vunce: Could you tell me what the yellow caps used at C15,C16,C25,C26 are ?. Are they all 47uf. Also same for C1 - C6 blue ones? . I like the color it gives to the board, rather than some of the others I have seen. 😉
Thanks all for the help,
Gathering parts and have a general question. Concerning R8,R9, what is a common output voltage from the DAC for the input to a preamp ? Is the 1k4 resistor enough (approx 1V rms) or does it need to be around 2V rms.
@ Vunce: Could you tell me what the yellow caps used at C15,C16,C25,C26 are ?. Are they all 47uf. Also same for C1 - C6 blue ones? . I like the color it gives to the board, rather than some of the others I have seen. 😉
Thanks all for the help,
Thanks Vunce,
Any idea on my first question about the value of R8, R9, to have proper voltage out to a normal pre amp.
I will study your dac closely.
Any idea on my first question about the value of R8, R9, to have proper voltage out to a normal pre amp.
I will study your dac closely.
Thanks again Vunce,
Mine are the Yarra type: Melbourne and Hakuin and one of the Aksa lender. So 1.5 sounds like a good value.
Mine are the Yarra type: Melbourne and Hakuin and one of the Aksa lender. So 1.5 sounds like a good value.
Hi guys. I need to sort out the pops and clicks and bangs I get when my system changes clock frequency. Source is Rpi into Ian FifoPi (not the new one) and fed with Mori clocks into Ian's Sinepi squarer.
Apparently the new fifopi q7vII has a constant clock output function which eliminated the pops. My older FifoPi has a 'mute' pin bit I have no idea what to do with it or if it is suitable. Have asked on the Ian thread but not too helpful as of yet.
Anyone else using external clocks that has solved this kind of issue.?
Thanks
Apparently the new fifopi q7vII has a constant clock output function which eliminated the pops. My older FifoPi has a 'mute' pin bit I have no idea what to do with it or if it is suitable. Have asked on the Ian thread but not too helpful as of yet.
Anyone else using external clocks that has solved this kind of issue.?
Thanks
I had the same problem with the JLSounds board and they also have a mute pin. But you need a separate mute board, that is placed right before the output, where you then connect the mute pin. Every time the clock is changed, the output is then muted. I guess there must be something similar from Ian?
I haven't seen anything from Ian and he hasn't offered anything up. Would you mind sharing more info on your mute board?!
The below copied from the Fifo manual...
Isolated MUTE signal. A logic high output indicates DAC should be muted. This signal is optional. Most DACs or DAC HATs do not need this signal.
The below copied from the Fifo manual...
Isolated MUTE signal. A logic high output indicates DAC should be muted. This signal is optional. Most DACs or DAC HATs do not need this signal.
http://www.jlsounds.com/mute.html
@kh5 The above info says that the mute can be active on both high and low states. How does user set the condition for the mute to be active?
@kh5 The above info says that the mute can be active on both high and low states. How does user set the condition for the mute to be active?
There's a jumper on the board, that probaly sets that. On the bottom in the middle. H3.
The question is, what voltage the FifoPi board outputs, and if it works with the JLSounds mute board. Depending on how important the problem is, it might be worth a try. The board is not very expensive.
The question is, what voltage the FifoPi board outputs, and if it works with the JLSounds mute board. Depending on how important the problem is, it might be worth a try. The board is not very expensive.