RJM Audio Emerald Phono Stage Help Desk

I've only listened to my Koetsu through a SUT (Hashimoto 1:40) into a 48k load, which reflects back to 30R to the cartridge. It will be interesting to hear it direct into the Emerald.

I decided to put in a 2x6 switch with 1% resistor ladders wired to allow me to select from 32R, 54R, 76R, 98R, 166R, 266R. The pot approach would have meant lower precision and potential mismatch between the channels. Once work gets out of the way and I can complete the build I'll listen for a while with the stock 100R, then try the switch.
 
I thought I'd chime in with regards to "why use a SUT?" I've tried the Emerald as a moving magnet stage for my Ortofon 2M Black and in combination with a CM-1254 SUT with both my Fidelity Research MC201 (my favorite) and a Denon DL103. I've also tried out the MC stage of the Emerald with the MC201. I prefer the MM/SUT configuration. It's just more dynamic in my system, along with other less obvious musical benefits. The Emerald is my second-favorite phono preamp. I like my SofTone Model 4 the best, and though it also offers MC playback, I also prefer MM/SUT on that phono preamp. All that said, the Emerald amplifying the 2M Black sounds very good, maybe as good as any MM I've heard in my system, but only on pristine records, entirely the cartridge's fault.

Other preamps with phono sections I've owned and liked: Superphon Revelation Dual Mono and the tube-burning Audible Illusions Modulus 2D. I'm old. :D
 
Some interesting findings

Tried a few r on signal path and gain


Takman Dale and susumu

The nice one is irc rn60 thin film for signal a lot more density and musical
The gain part caddock square ones is very nice

Which thin film did you settle on ? Once I've nailed the load I prefer for the Koetsu I planned to replace the switch with one of these...

Charcroft Z-Foil and S-Foil | Hifi Collective
 
Which thin film did you settle on ? Once I've nailed the load I prefer for the Koetsu I planned to replace the switch with one of these...

Charcroft Z-Foil and S-Foil | Hifi Collective

The caddock mk132 is good for gain Clear and punchy. Good width

Loading I prefer rn 60 by irc.. It's nos.. It have the most density, texture and very very liquid and musical. Caddock dont sound especially good there too soft. Dale too clean. Takman too light

I think tkd resistors is very similar to irc

The character compliment emerald. Which benifits from a heavier sounding combination

Also.. Raise the gain... It sound much much better with higher gain. Cardas litz for internal is great match for emerald
 
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For loMc.. Try 400 as start .. Usually works best {friend have Koetsu and I recalled 400} Lyra also 400

If sut style.. The input 47k+100pf

But be careful... Signal is small and best is burn in using a radio for 3 to 5 days before listening.. The basic character is not revealed yet .

It can be very very different
 
Shoot... I forgot used up the resistors


Anyway to show how good is 56db, 100pf & 47k loading about 1 week burnt in
Using a cheap ortofon om10 { my burning in cartridge}
YouTube
YouTube example

The gain really helps to open up, more musical and improved stage size in return.. And the added capacitance improved weight and tone bringing the vocal less recessed.

It's a nasty recording. Friend played it somewhere else and his ear bled.

Play around with it and you will be pleasantly supprised
 

rjm

Member
Joined 2004
Paid Member
Glad it worked out for you. It makes sense for high gain to sound more open, since the feedback applied is very much reduced. Note that distortion in principle is also increased, so this is - as always - a zero sum game.

The Emerald in MC mode operates like the Phonoclone, with 30dB and 30dB midband gain on each op-amp. In MM mode the gain of the input stage is only 10 dB, whereas if I was making a purely MM stage, I would split it 20/20 between IC1 and IC2. The gain of the second stage in the Emerald cannot be adjusted easily, which is why we are where we are. Not that I consider 10 dB gain setting to be a problem exactly, but your observations do reinforce my view that the Emerald is a MC phono stage first and a MM phono stage second.
 
Yes Richard

One of the thing that's diff is how much a cymbal kick drum sounds much more real. There is some compromise. Depth is closer but wider Soundstage so.. I think it's better

I did think of that but clueless how to do it

Like preamp we play with the feedback to achieve the character

Also for Mc we tried but it becomes noisy at 70 db but much better . So it need to be tweaked somewhere

I did add a ferrite beads at ground signal input.. It does helps with the noise
 
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