Monica 2 DAC - World-Designs-Forum

Deco-Doctor · #1 21st January 2007, 01:28 PM

DIY Paradise Monica 2 TDA1545A non oversampling DAC with 417A grounded grid output stage. Triodes loaded with 200H plate chokes. Yummy....

Martin

Deco-Doctor · #2 21st January 2007, 01:35 PM

I added some info, but for some reason it did not appear

Anyway it is a Diy Paradise Monica 2 TDA1545A non oversampling DAC with a 417A grounded grid output stage, both triodes are loaded with 200H plate chokes.

Sounds very nice indeed.

Now to build a proper box for it....

Martin

Greg. · #3 21st January 2007, 08:13 PM

Hi Martin,

Several get this error when trying to add text to gallery pictures. Check out the FAQ. Your text needs to be added after your picture has loaded, but you also need some text (a letter only) to get the original picture to load. Nice looking DAC by the way.

Best wishes,

Greg

Deco-Doctor · #4 21st January 2007, 08:47 PM

Quote:

Originally Posted by Greg.

Hi Martin,

Several get this error when trying to add text to gallery pictures. Check out the FAQ. Your text needs to be added after your picture has loaded, but you also need some text (a letter only) to get the original picture to load. Nice looking DAC by the way.

Best wishes,

Greg

Hi Greg

Thanks. Thats the first time I posted a picture so I was not sure how it would turn out. 'If all else fails then read the instructions' is my normal modus operandi.

The DAC is in a temporary box with a breadboard PSU, just playing around with the PSU and operating points for the 417A's before it gets tidied up.

Regards

Martin

Rob042 · #5 26th January 2007, 03:52 PM

Martin
looks good - have the 1543 outputing via a pair of 12b4a's and have to say its one of the best sounding diy dacs I have put together.

Have you tried battery supply for the dac?

Rob

Deco-Doctor · #6 26th January 2007, 08:36 PM

Quote:

Originally Posted by Rob042

Have you tried battery supply for the dac?

Hi Rob

No I've not tried a battery supply yet, there is some discussion about a battery supply with Monica 2. Some prefer the SMPS that Yeo supplies. What do you think about a battery supply?

I am using a regulated 12V 1.5amp power supply which is sounding pretty good. The battery supply will make the finished article rather big with all the components for the output stage supply as well, plus the added inconvenience of the charging arrangements. Needs a bit of thought to get it right.

I guess you are driving the grids of the 12B4A's, nice low mu tube. The 417A's I am using here are running in grounded grid which provides a nice low impedance load for the passive I/V output of the 1545A. It sounds mostly pretty stunning, with just the very slightest glassy edge on some female voice recordings (sopranos).

Martin

Rob042 · #7 29th January 2007, 01:48 PM

Martin

found any psu so sound a touch muddied conpared to a battery with a couple of caps. ( adding caps to work with the battery does add a certain something which I feel gives the set up the edge over a mains supply)

Rob

Deco-Doctor · #8 29th January 2007, 07:34 PM

Quote:

Originally Posted by Rob042

Martin

found any psu so sound a touch muddied conpared to a battery with a couple of caps. ( adding caps to work with the battery does add a certain something which I feel gives the set up the edge over a mains supply)

Rob

Thanks Rob, I might just give the battery a try before I rip apart the breadboard power supply.

The Monica 2 is certainly a fantastic little DAC with the grounded grid triode output stage, huge amounts better than I expected. I bought it to use with my Squeezebox 3, but I now find myself using my Arcam FMJ CD23 as a transport for the Monica 2. The best digital sound I have yet heard, brilliantly detailed and musical. I love it

, so much that I can't stop listening for long enough to tidy it all up!

Martin

Rob042 · #9 30th January 2007, 10:08 AM

Martin
"much that I can't stop listening for long enough to tidy it all up!"
now there the a good sign.
mine is still in half a plastic box,with battery under the transport,and the valve section psu in an over sized box.

don't think I'll get around to cleaning up.

Rob

Deco-Doctor · #10 30th January 2007, 02:02 PM

Quote:

Originally Posted by Rob042

Martin

mine is still in half a plastic box,with battery under the transport,and the valve section psu in an over sized box.

Rob

Rob

Looks much tidier than mine. I see you are using russian K75 PIO coupling caps in the output, looks like the exact same caps as I have in mine! I like these a lot.

Martin