I’ve been on a path to replace my vintage Jolida JD502 tube integrated amplifier for a year or so. It’s been re-capped, had resistors changed, and holds bias perfectly. It is currently powered by GL KT88 output tubes (sometimes swapped for TungSol KT-120s), and using NOS JAN-GE 12AX7WA and NOS Sylvania 5751 triple mica black plates for the smaller tubes. I am very pleased with the sound, but occasionally run out of steam and hear some strain and compressing of dynamics when I crank it.
My speakers are LSA Statement 100 monitors. They’re a sealed 2-way design with ribbon tweeters, 6.5” woofers, rear passive radiators, present a mostly 8ohm load, and come in at about 87db efficiency. That combined with the Jolida’s 70-80W/ch *and* the very large, open family room, kitchen, entry, dining room, and 20ft ceilings result in the need to “crank it” sometimes. The Jolida just flat runs out of gas in that scenario, so I’ve been looking for more powerful monoblocks.
Upstream, a Lumin U2 feeds a Lampizator Atlantic 3 TRP DAC (balanced, and volume control options). A Sophia Aqua II regulates power, and a matched quad of NOS Siemens F2A tubes handle output duty. The TRP is used as a preamp, and feeds the Jolida directly via SE connections.
To the point of this thread… I’ve been looking at amp upgrade options and have been demoing amps in my home. Specifically, a pair of Modwright KW99 monoblocks (sounded painfully sterile and cold), a pair of custom Class D monoblocks based on the latest Pure module (sounded better, but no emotional engagement), and currently new Audio by Van Alstine DVA M750 monoblocks.
The DVA M750s replaced my Jolida, so I had to find another AC cable for the other monoblock, and I had to split the REL high output cable in order to connect my S/510 to both amps. The DVA 750s aren’t Class D, so the REL connection was the same as for Class A/B amps. I also connected the TRP DAC to the M750s with XLR cables, as that’s the only input they suppprt.
When I first connected the M750s I noticed 2 things: first, the speaker binding posts at the rear of each amp were slightly loose meaning they would rotate in the chassis when trying to loosen/tighten them. Opening the chassis, I was able to carefully tighten them enough to cease their rotation on the back panel. (Also the far left binding post pair as viewed from the rear are the first in line, with the pair to the right being daisy chained off them. Probably not a huge deal, but if you want the shortest, cleanest path use the left pair of binding posts).
Second, once powered up, a slight audible hum was coming from the right amp chassis. This was using the AVA supplied, basic AC cable. The hum did not come through the speaker at all, but was noticeable from 3-4ft away. As soon as I replaced the stock AC cable with a Pangea Audio AC-9SE MkII (my default AC cable for amps), the hum disappeared completely and has not returned.
The M750s have been in play for a few weeks now, despite traveling a bit for the holidays. They’ve got approx. 75 hrs on them, and I’ve been able to get some critical listening sessions in here and there.
I’ll post more impressions in follow on posts, but I wanted to give at least a quick one…
Initial power up and playing, the sound was a little lean, but I could hear that they were better than the other amps I had tried recently. Around hour 5 I noticed an uptick in warmth and upper end clarity (could have been attributable to the MOSFETs getting heat soaked and just sounding better). My notes show that at ~25 hrs “silkiness, air, and some tubey magic crept in. Soundstage got deeper, highs are incredibly clear and pure. Had to adjust the REL crossover freq up and turned volume down by 1ea. Perfect.”
At the 40hr mark, my notes say “really opening up, very smooth, clear, agile, and spacious. Vice grip on the speakers.”
Now at ~75hrs, I am hearing subtle upper frequency details that I’ve never noticed before. Dynamics are extreme and VERY fast. But small, ambient sounds are presented with amazing clarity and soundstage presence right alongside those big macro dynamics. The M750s also seem to be getting a slightly warmer signature, but it does take a few hours of being powered up to really get there for each listening session.
Overall, I am very pleased with them so far. I’ve read in other threads and forums that AVA doesn’t suggest that much burn in time is necessary, but consumers have said the opposite, usually requiring 200-400hrs to really get AVA gear to sing. With ~75hrs, I’ve got a bit more to go. More to follow…
My speakers are LSA Statement 100 monitors. They’re a sealed 2-way design with ribbon tweeters, 6.5” woofers, rear passive radiators, present a mostly 8ohm load, and come in at about 87db efficiency. That combined with the Jolida’s 70-80W/ch *and* the very large, open family room, kitchen, entry, dining room, and 20ft ceilings result in the need to “crank it” sometimes. The Jolida just flat runs out of gas in that scenario, so I’ve been looking for more powerful monoblocks.
Upstream, a Lumin U2 feeds a Lampizator Atlantic 3 TRP DAC (balanced, and volume control options). A Sophia Aqua II regulates power, and a matched quad of NOS Siemens F2A tubes handle output duty. The TRP is used as a preamp, and feeds the Jolida directly via SE connections.
To the point of this thread… I’ve been looking at amp upgrade options and have been demoing amps in my home. Specifically, a pair of Modwright KW99 monoblocks (sounded painfully sterile and cold), a pair of custom Class D monoblocks based on the latest Pure module (sounded better, but no emotional engagement), and currently new Audio by Van Alstine DVA M750 monoblocks.
The DVA M750s replaced my Jolida, so I had to find another AC cable for the other monoblock, and I had to split the REL high output cable in order to connect my S/510 to both amps. The DVA 750s aren’t Class D, so the REL connection was the same as for Class A/B amps. I also connected the TRP DAC to the M750s with XLR cables, as that’s the only input they suppprt.
When I first connected the M750s I noticed 2 things: first, the speaker binding posts at the rear of each amp were slightly loose meaning they would rotate in the chassis when trying to loosen/tighten them. Opening the chassis, I was able to carefully tighten them enough to cease their rotation on the back panel. (Also the far left binding post pair as viewed from the rear are the first in line, with the pair to the right being daisy chained off them. Probably not a huge deal, but if you want the shortest, cleanest path use the left pair of binding posts).
Second, once powered up, a slight audible hum was coming from the right amp chassis. This was using the AVA supplied, basic AC cable. The hum did not come through the speaker at all, but was noticeable from 3-4ft away. As soon as I replaced the stock AC cable with a Pangea Audio AC-9SE MkII (my default AC cable for amps), the hum disappeared completely and has not returned.
The M750s have been in play for a few weeks now, despite traveling a bit for the holidays. They’ve got approx. 75 hrs on them, and I’ve been able to get some critical listening sessions in here and there.
I’ll post more impressions in follow on posts, but I wanted to give at least a quick one…
Initial power up and playing, the sound was a little lean, but I could hear that they were better than the other amps I had tried recently. Around hour 5 I noticed an uptick in warmth and upper end clarity (could have been attributable to the MOSFETs getting heat soaked and just sounding better). My notes show that at ~25 hrs “silkiness, air, and some tubey magic crept in. Soundstage got deeper, highs are incredibly clear and pure. Had to adjust the REL crossover freq up and turned volume down by 1ea. Perfect.”
At the 40hr mark, my notes say “really opening up, very smooth, clear, agile, and spacious. Vice grip on the speakers.”
Now at ~75hrs, I am hearing subtle upper frequency details that I’ve never noticed before. Dynamics are extreme and VERY fast. But small, ambient sounds are presented with amazing clarity and soundstage presence right alongside those big macro dynamics. The M750s also seem to be getting a slightly warmer signature, but it does take a few hours of being powered up to really get there for each listening session.
Overall, I am very pleased with them so far. I’ve read in other threads and forums that AVA doesn’t suggest that much burn in time is necessary, but consumers have said the opposite, usually requiring 200-400hrs to really get AVA gear to sing. With ~75hrs, I’ve got a bit more to go. More to follow…
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