You have the parallel inputs for that.
Solder a cap to a phonoplug and insert in the spare input.
Strange that you have to use high gain, the 680EE at 4,1mV nominal is not that low output....
...although it is a 40 year old cartridge, maybe it got demagnetized somehow ?
Solder a cap to a phonoplug and insert in the spare input.
Strange that you have to use high gain, the 680EE at 4,1mV nominal is not that low output....
...although it is a 40 year old cartridge, maybe it got demagnetized somehow ?
Honestly dunno, it's true that my amp really needs an high gain to work well anyway I tried also with a dap not connected with electrical plug but with batteries and the same noise, I guess Richard is right it's a matter of opamp, have I to resolder their socket or I have to change them at all?
Hi all. Very interesting thread - all 48 pages! 🙂
I’m about to build this and looking very much forward to it. I’m wondering how much power does these boards actually draw? I have an old toroidal transformer with 2x14,4V @ 0,65A. I know that’s under the recommendation but does the boards really need 25va? 🙂
Anyway thanks a lot for a very nice project!
PS: For those of you who have the transformer and rectifiers in the same box as the boards, how is your noise levels/do you hear any interference or hum from those?
PPS: best place to buy Jantzen or Mundorf caps within EU? 🙂
I’m about to build this and looking very much forward to it. I’m wondering how much power does these boards actually draw? I have an old toroidal transformer with 2x14,4V @ 0,65A. I know that’s under the recommendation but does the boards really need 25va? 🙂
Anyway thanks a lot for a very nice project!
PS: For those of you who have the transformer and rectifiers in the same box as the boards, how is your noise levels/do you hear any interference or hum from those?
PPS: best place to buy Jantzen or Mundorf caps within EU? 🙂
Hi Brinker - do you get any noise/hum problems with the transformer and rectifiers next to your boards?
Thank- og god aften 😉
Just to report that I've just built the Emerald, following the excellent build guide, using the standard BOM from mouser (except for the electrolytic capacitors which I had already), and an aluminium cases from aliexpress
I had already built the vsps, so I used the same external power supply
It worked first time without issue. No hum at all, just a tiny amount of hiss at max volume
It sounds great. I will do a comparative listening test vs the VSPS later.
I had already built the vsps, so I used the same external power supply
It worked first time without issue. No hum at all, just a tiny amount of hiss at max volume
It sounds great. I will do a comparative listening test vs the VSPS later.
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2X12 volt 25VA transformer is about 2x1 Amps. So way overrated. Why do some brands (like NAIM) use heavier transformers is that they say it simply sounds better then a transformer that can just do the job. NAIM use for their preamps and phono preamps separate psu's, like the Hicap, with transformers of about 300 or 500VA. It's up to you. Myself I use a transformer of 100VA.
I'm wondering if anyone has tried a discrete MC input into the Emerald? After reading Douglas Self's Electronics for Vinyl it seems a discrete approach may yield better results than an IC for the MC component. I'm looking at running this circuit via a Sigma 11 PSU at 24V. @rjm Wondering if I need to be considered about overloading the MM portion of the Emerald if the MC is at that voltage. Any advice there?
@Calvdart The Emerald can be used with a separate head amp, or step up tranformers, by switching it to the low gain MM setting.
Using a pair of 2SK170s (assuming you can find them!) as a head amp will result in lower self-noise but worse PSRR and higher distortion figures.
Compared to op-amps like the OPA27, the PSRR of a resistively loaded FET stage is ~zero. You can hear your power supply as clearly as you can hear your LP -- so you better have a really quiet power supply!
It may or may not sound "better". That's going to depend if you like the FET coloration.
I built a FET-style phono pre a while back, I quite liked it ... but I liked the Emerald better. More relevant is the fact that op-amps are much, much easier to work with.
Using a pair of 2SK170s (assuming you can find them!) as a head amp will result in lower self-noise but worse PSRR and higher distortion figures.
Compared to op-amps like the OPA27, the PSRR of a resistively loaded FET stage is ~zero. You can hear your power supply as clearly as you can hear your LP -- so you better have a really quiet power supply!
It may or may not sound "better". That's going to depend if you like the FET coloration.
I built a FET-style phono pre a while back, I quite liked it ... but I liked the Emerald better. More relevant is the fact that op-amps are much, much easier to work with.
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Thanks for the reply. I definitely don't have any 2SK170s around so will use the Toshiba LSK170s instead. I'm also looking at the four transistor Aikido MC Pre as a BJT based option for better PSRR. Mostly I just want to play around and see what I like, learn a bunch, and get deeper into the DIY of phono stages.
Who knows, if I use the AMB Sigma 22 for the PSU for both the MC portion and the emerald, I could even try to roll some discrete opamps into the Emerald. That is if I could justify the additional $350 in expense on it, but that's part of the fun too!
Who knows, if I use the AMB Sigma 22 for the PSU for both the MC portion and the emerald, I could even try to roll some discrete opamps into the Emerald. That is if I could justify the additional $350 in expense on it, but that's part of the fun too!