Have you tried going onto their website - I believe you can buy directly from them there
Andrew, yes, but the page indicates it's a request for quote. I'll proceed with the RFQ and I'll report back. BTW, what is the experience from ordering from RS Components when their stock is on the other side of the ocean? I see they have stock on the transformer and binding post on your side, but 0 stock on this side. Digi-Key and Mouser have lead times.
Javier, I used the OPA1651's in the phono stage for the line stage and the filter, although you can also use NE5534A as long as you fit the comp cap. I could see no difference in measured performance between the two builds that I did.
The reason I used the LM4562 for the MM gain block and the front end regulator stages (both MM and MC) is that they have superb PSRR performance - I may stand to be corrected, but I think for the money, they are still the best out there. Importantly, the PSRR extends all the way out to about 200 kHz where its still a very decent 90 dB and 50 dB with 200 mV pk-pk on the supply rails - but this latter case will never happen in the X-Altra MC/MM because the rails are regulated anyway. Its also a very quiet opamp with great output current capability.
I would be reluctant to encourage anyone to change to another opamp because the design was optimized from the compensation aspect for the LM4562 - I don't know if there would be instability issues if it is changed for something else.
Anyway, I think the sonic signature of the X-Altra MC/MM on MM input inasmuch as it exists would be that of the JFET input stage.
The reason I used the LM4562 for the MM gain block and the front end regulator stages (both MM and MC) is that they have superb PSRR performance - I may stand to be corrected, but I think for the money, they are still the best out there. Importantly, the PSRR extends all the way out to about 200 kHz where its still a very decent 90 dB and 50 dB with 200 mV pk-pk on the supply rails - but this latter case will never happen in the X-Altra MC/MM because the rails are regulated anyway. Its also a very quiet opamp with great output current capability.
I would be reluctant to encourage anyone to change to another opamp because the design was optimized from the compensation aspect for the LM4562 - I don't know if there would be instability issues if it is changed for something else.
Anyway, I think the sonic signature of the X-Altra MC/MM on MM input inasmuch as it exists would be that of the JFET input stage.
This post is to advise that there have been a few minor changes to the BOM for the X-Altra. There were some discrepancies between the PCB and the BOM.
Please use the latest BOM for your build
X-Altra RIAA Phono EQ Preamp
As always, any questions, let me know.
Please use the latest BOM for your build
X-Altra RIAA Phono EQ Preamp
As always, any questions, let me know.
LSK389
Hi, I'm struggling to source these at a sensible price here in the UK. Not sure if you dealt through Micross Bonsai? They gave me a similar price to Sonidos but a very large min order. Cheaper for me to buy from the states, but even that I'm struggling since the carriage is outrageous given the weight / size of the parts..
I do have a pair of 2SK389, but probably not suitable?
Hi, I'm struggling to source these at a sensible price here in the UK. Not sure if you dealt through Micross Bonsai? They gave me a similar price to Sonidos but a very large min order. Cheaper for me to buy from the states, but even that I'm struggling since the carriage is outrageous given the weight / size of the parts..
I do have a pair of 2SK389, but probably not suitable?
I just took a look at this - yes this will work and the pin spacing and diameter are al ok. these caps provide additional rail filtering on the low noise power supplies. Here is the link:-
https://www.mouser.co.uk/ProductDet...ZCacnG3T%2Blk7SXy4tY4E98Y0xwrc6M3gX2LjrjaGg==
Hi Bonsai, they are 2SK389 BL grade. Unfortunately they are the old leaded SIL package not SOIC, so would be a nightmare to adapt. But if they would work I will consider it. On another subject the Galaxy cases are nice. I used a couple of the very same for a DAC I built. They are nice cases but its worth mentioning here, that they are anodised. So you do need to take particular care, to make sure each part is connected to earth - bonded...
Wish I’d known that when I designed the PCB . . .
You could dead bug wire them until you could get the LSK parts - just use 1 or two strands of multi core and keep the leads very short. This will enable you to confirm everything is working ok. The ‘B’ grade is what I used.
The Linear Systems parts are really fantastic, but they don’t help themselves with availability I have to say.
You could dead bug wire them until you could get the LSK parts - just use 1 or two strands of multi core and keep the leads very short. This will enable you to confirm everything is working ok. The ‘B’ grade is what I used.
The Linear Systems parts are really fantastic, but they don’t help themselves with availability I have to say.
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