When I wrote the review of the Jasmine LP2.0 SE phono stage, I suggested that it might lend itself to tweaking. I didn’t mean to denigrate the parts quality, and still don’t, because you’ll see these parts in products costing more. Considering the rather low price, the outboard power supply, and the nice metal work, I wouldn’t have been surprised to see cheaper parts. I was happy enough with the quality, both in build and sound, that I purchased the review sample. Both Fernando Cruze (US Importer for Jasmine) and I, nearly simultaneously, launched into modifications of the LP2.0 SE. The simple circuit and the design of the board lends itself to tweaking. During the process, we didn’t really trade ideas, and we took different directions.
I’ve been modifying and tweaking classic gear for years. If you think that today’s fanciest products are way more advanced than something from forty years ago, think again. Everything old is new again. Today’s single-ended amps and horns are refined products based on eighty-year-old technologies. I’ve heard a 30-year-old Japanese direct-drive beat a contemporary $40,000 turntable. The cult following of Garrard, Thorens and EMT is based on solid engineering and quality craftsmanship. You won’t see a Garrard or Thorens in a stock plinth though—they can only shine when mated to plinths and tonearms of the highest quality. If you don’t have the money for the state-of-the-art equipment reviewed here and elsewhere, don’t despair. Your purchase of an entry-level high-end product, like this Jasmine phono stage, can serve as the starting point for even better sound (other products like RB300 come to mind). If you can’t solder, then start learning. I wasn’t born with a soldering iron in my hand, but after years of practice, I’m doing quite well. The good thing with the Jasmine is that it’s easy to modify.
My starting point with most preamp modifications is with the power supply. Much is made of coupling caps, and I can’t argue with those who put their money there first. But, in my experience, the rather lame electrolytic caps that find their way into many of our audio products are more of a limitation to performance than a decent, metalized polypropylene coupling cap. After hearing transistor products that used servos instead of coupling caps, and after upgrading the god-awful sounding tantalum caps in other transistor amps, I decided that electrolytic caps are a bad idea in general. Most have ESR values that change with frequency. They age and change value. They change value with different temperatures. They fail catastrophically and usually without warning. Yuck! Phooey!
With the Jasmine, it’s actually a lot better than that. The coupling caps are metalized polypropylene and the power supply electrolytics are generously uprated in voltage and capacitance. Still, the designer left areas on the board to try larger coupling caps and places to add more power supply capacitance. This is good.
I asked for some suggestions and received not real consensus from the answers. I’d tried Black Gates in the past, but didn’t notice a proportional bang for the buck I spent. I used Silmic and Muse for coupling caps and they were pretty good, so I looked at those values. Also, several people spoke highly of the Panasonic caps. I decided on Panasonic FM 1000uF at 50VDC, Nichicon FW 2200uF at 63VDC and Nichicon Muse ES 220uF at 50VDC; the Muse ES might be the best available since it is bipolar, but it is also much larger than other caps, limiting where you can put it. I chose the caps based on two criteria: adding more microfarads, and lowering ESR. All things being equal, more capacitance should give better bass and dynamics. All things being equal, the lower ESR should make for quieter backgrounds, prettier highs and more dimensional sound—always does for me. The Nichicon FW 2200uf cap should add grunt; the Muse ES should help musicality; and the Panasonic was thrown in for good measure. Just for the sake of overkill, and since I had them, I piggybacked five (per channel) 1uf at 100VDC TRW polyester film caps made in the ‘80s. They are hard to find, but are excellent in transistor power supplies.
I wanted to go retro with the coupling caps so I experimented with several NOS PIO caps. John Semrad, maker of fine panzerholz turntable plinths, supplied me with some interesting varieties to try out and I wound up settling on some military spec polycarbonate and tin-foil-in-oil 1uF at 100VDC. I had also tried some Vitamin Q that didn’t sound like I expected. I found out that they were metalized mylar in oil. They were quiet and very dynamic, but the sound was slightly phasey with a woolen sounding midbass.
The biggest gains were with the power supply caps. It took a bit of cramming, but the added capacitance and higher quality caps improved every aspect of sound. If I were more patient, I would have done one cap at a time, but life is too short and that wasn’t going to happen. At the output stage, I had the Panasonic FM and Nichicon Muse ES stacked, one cap at a right angle to the legs of the other cap, with stacked mylar film caps on the bottom of the board attached to the legs of the Panasonic that I left about ½ cm longer than needed. Mylar has a slightly higher dielectric constant than polypropylene, but its very low ESR makes it a good power supply choice. It wasn’t pretty, but with the space I had, it was the only arrangement I could get to work. The input stage got the Nichicon FW 2200uf cap.
There is plenty of room on the board for experimenting with the output stage coupling caps. Unfortunately, the space for the coupling caps after the first stage, which amounts to a headamp, I think, is much tighter. I left it as-is. The cartridges I was using were high output, and if I were using a low output cartridge at the time, then I might have tackled the other coupling caps (they are Wima, which are good).
After these mods, the Jasmine had a better tonal balance. Compared to the best phono stages I’ve heard, it had a slight rolling-off in the bass and a hint of forwardness in the midrange. Please don’t think that I’m saying the Jasmine was “forward sounding” or aggressive in stock form. It wasn’t. I’ve heard several orders of magnitude more aggressive midrange from some 6dj8 phono stages. I’ve heard several 12ax7 phono stages with little or no bass. After the mods, the Jasmine’s bass was deeper, with much better impact. There was less overhang with the mods, making bass lines speedier, and more propulsive. Rhythms were easier to follow.
On top, highs were sweeter with more authentic textures. Differences between cymbals were more audible. Top to bottom, the sound was cleaner, faster and more transparent.
The only thing that didn’t improve was dimensionality. A trusted friend felt that I should try different coupling caps. I have to agree. I only used two different NOS oil caps that I had access to. All the improvements I heard could be from the power supply mods. A note for users of older gear: electrolytic caps age, losing their ability to supply current when needed, and to filter out noise. As they age, their ESR goes up and capacitance goes down. It’s better to classify power supply caps as a normal service item, like having your transmission or differential fluid changed at 100,000 miles (or whatever your auto maker recommends). Fernando Cruze, Jasmine’s U.S. importer, took a slightly different approach, upgrading the wiring, phono jacks and changing the coupling caps to Mundorf. This reinforces my original point that the Jasmine is a very “tweakable” preamp; none of us messed with resistors. That exponentially adds to the choices you could make: metal film, metal foil, wire wound, tantalum, carbon film or carbon comp (for the classic sound).
I’ve lost none of my enthusiasm for the stock Jasmine LP2se. It’s a flexible phono stage at a very attractive price. Jasmine made very good decisions on circuit design, parts choice and build quality. You could enjoy this phono stage for many years, upgrading its parts as time and money permit. If I do more experimentation or get other feedback, I will keep the readers informed. Now more recommended than the first time I recommended it.
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