Others opinions on the new MHDT Stockholm DAC?

Phil,

I picked up a modded Havanna, based on Sean Caseys reommendaton after listening to yours last spring. This is a fantastic DAC. Mine has thefollowing mods:

1) The replacement of the two input capacitors with Jensen copper foil paper in oil in aluminum case ones.
2) The replacement of the cap behind the input caps with a Jupiter HT.
3) The replacement of the two output coupling caps with Jupiter HTs.
4) The conversion of the RCA coaxial input connector to a BNC connector for true 75 ohm compatibility (I will include a BNC to RCA adaptor).
5) The substitution of a Hi-Fi Tuning Fuse for the stock fuse.
6) The substitution of the stock tube with a Western Electric JW396A/2C51.

I did not do the mod's as the previous owner had it done. I am also now curious about the DAC chips. I need to pop the top and see which ones are in it.

In the positive feedback review they mention the following about replacing the dac chips with AD1856.

"Mhdt designed the Havana so it would delight tweakers everywhere: Jiun-Hsien told me that “There is a secret that we only tell Havana users, that if they want to they can replace the stock PCM56P chips with AD1856 chips (which are pin to pin compatible), without changing any components in the Havana DAC. We assembled the Havana with IC sockets for the two PCM56P chips. We purposely installed these two IC sockets so that Havana users could experiment with further possibilities if they wished, like the AD1856 chip, or others.”"

Did you ever try the AD1856 in your Havanna? If no, do you know anythin about it?

Thanks

Todd

Todd,

Yeah, Sean likes the Havana! I have the Balanced version, and I recently bought a second one for my Druids system.

The Balanced Havana comes stock with PCM56P-J, which people seem to agree is a slight improvement over the PCM56P that comes stock in single-ended Havana. I went further and replaced the J chip with Malaysian PCM56P-K, from a trusted source (Mouser) and there is no question these improved resolution a bit, have a more spatially rewarding presentation, and firmed up the bass resolution and quality audibly. I now have moved this DAC to my Druid V system.

In my Def4 system I installed the more recently-acquired Havana Balanced, and swapped out the stock chips with AD1856. Keeping in mind that the Balanced Havana sounds meatier and more tone-dense than single-ended Havana (and of course I have to buy 4 chips), the AD1856 is a different sound still within Havana strengths. On other forums, there's been some criticism about the AD1856 making Havana sound "electronic." I don't agree with this -- I can usually trace that criticism to associated gear and to headphones. AD1856 chips give the Havana more resolution, somewhat leaner more truthful (less euphonic) bass, and lays out a more precise soundstage and placements.

It's not shape-shifting or revolutionary, but there's a little less of the boomy, bursty fun of the PCM56P-J or K. You retain the basic tonality strengths of this circuit. Again, to get the best sound you have to rest these DACs on the right footers. I've tried a lot of contenders, and Aurios Media Bearings still win out. I imagine Rollerblocks would do OK too.

My next upgrade will be replacement of the output caps, but there's less available room relative to four being needed than for the two in the single-ended DAC, so my choices are fewer. Still contemplating that.

All the mods done to your DAC prior to you buying are good interventions. I'll just add that the WE 396A/2c51 is really a 396 as far as I can see, compared to a real Bendix or Tung-Sol 2c51. I encourage you to find one of those. The Bendix 6385 is allegedly the grail tube in these DACs, but I have found it slightly bleaching of tone, while giving very good definition. I may return to them for the Druid5 system DAC with the PCM56P-K. The 1964 Bendix 6385 is definitely not the best match to the AD1865. My real 2C51s are great with that chip.

Whether you will prefer the AD1865 in a single-ended Havana depends on the rest of your system and your hot buttons. Hard to predict without knowing more.

Phil

I am currently running my single ended Havana with the PCM56-K chip set and he WE396A. This is the best combination for the rest of my system. If I want to tighten up the presentation a bit some fun tubes to try are the vintage Russian 6H varieties such as the 6HNE, 6H3N-H or a 6H3N-AP. All of these all sound similar to each other and the best part is they only cost $2.00 each on ebay so you have nothing to lose.

Thanks Phil, I'll probalbly try the K chips.

System where the Havanna is as follows:

Cayin A-50T integrated with a full set of genelex gold lion toubes on input and output stages.

Havanna DAC being fed by Squeeze Box Touch with a welbourne labs power supply.

All ZU event cabling

Zu Essence upgraded to the HO drivers.

Hmm, why bust a gut getting this DAC to sound 'right'. Have any of you guys tried the Audio Note DACs? They are NOS and No filtering, and have tubed power supply and analogue boards.

Fir me, the NOS and no filtering is 70% of the signature i.e. no digital edge and an organic smooth sound. Then the quality of the supply and output stages and the sum of the parts is the remaining 30%.

I would recommend an Audio Note 2.1 Factory or an Audio Note 3.1 kit from Canada if you are a tweaker. The kits are great quality on a budget, and have LOTS of parts upgrade and circuit weak possibilities, aside form the tubes.