Modwright upgraded Musical Paradise MP-D2 v.2
I bought a used Musical Paradise from a fellow AC member about six months ago and really enjoyed it over my Metrum Acoustics HEX. The HEX is quite neutral but can sound a bit thin on certain material. I decided to try a DAC with a tube analog section and the D2 came up for sale on AC for a reasonable price.
The first thing I noticed about the D2 was the bass. Much, much fuller and slightly bloated. Mids were richer and the soundstage increased in width and depth. Treble was nice and smooth but a bit reticent, as if it were damped down.
I liked it better than the HEX overall so the HEX was retired. I listened to the D2 for many hours with great pleasure when Dan Wright opened a thread in his circle about having the itch to find some new gear to apply his upgrade magic to. Knowing the Modwright reputation I got curious as to what Dan could do. After establishing contact Dan gave me his plan which was simply to evaluate the unit and find any weaknesses. Then plan out the upgrade. Dan found the overall design to be quite good and felt that the circuit was not optimized for the 6922 tube (specifically bias) and that the power supply could use some better regulation downstream from the rectifier tube. We discussed his plan and I said go for it!
When I got the unit back I had a little glitch in my audio chain, the tubes in my preamp wore out to the point the one triode in one of the four 12AU7’s in the circuit read “23” when the minimum is “46” (TV-7D/U tester). So after some trial and error (read bad tubes in my stash) I got it up and running again.
Finally a chance to listen to my newly tweaked MP-D2! First up is Jesse Cook “Beyond Borders” ASIN B073XVMW17 both the title cut and Double Dutch followed by AfroCelt Sound System Vol. 2 “Release” ASIN B001DPC3VA Big Cat and Vol. 3 “Further In Time” Colossus. These tunes have a lot of complex passages, tons of bass, and combine acoustic and electronic instruments to paint their sonic canvas. The bass bloat is now gone but bass is still full and deep. I think the bloat was masking some of the bass definition as well.
Mids and treble is fuller and more open, a bit more forward but that includes an increase in front to back depth of the soudstage. It was about 4-6 feet before, and mostly forward of the front baffles. Now it is about 6-8 feet deep and reaches behind the front baffles much further.
Next up was John Coltrane "Blue Train" ASIN B001KP0AKY RVG Edition the title cut Blue Train was reverb city as expected. Rudy had great ears! JC was followed by Joni Mitchell's Blue from the album of the same name, ASIN B000002KBU, for a taste of female vocals and Joni's smoky voice was conveyed perfectly. I finished up with KT Tunstall's Blackhorse and the Cherry Tree from " Eye To The Telescope" for some gritty rockin' tunes.
To sum up the Modwright mods, the primary benefit is better top to bottom balance, along with a deeper soundstage, and clearer mid through treble range. Big improvements all around and I heartily recommend it!
Good job, Dan!
BTW, besides the Modwright mods which consisted of a voltage regulation board and proper biasing resistors I installed four Mundorf S/G/O caps in the output coupling positions and four matched and balanced JJ E88CC gold pin tubes.
