But you can still make an informative check regarding the tracking geometry across the transcription arch.
a good used TT
A bit OT, but fast rewind to some seven thousand posts ago and I've stepped upon a trigger for my curiousity.
Reading around, I have already made a nice list of some carts (Denon 103R, Ortofon SPU, Benz ace) and SME IV arm (for an ex.) as possible upgrades from Rega Planar III/Goldring 1012 MM combo. But when it comes to TT I'm clueless. If something springs to your mind in that price range, I'm all ears. Better in PM, I guess.
good point Salas
I Thinks we can live well with a good used TT 500/ 700€ or a diy Lenco , put a good mc 0,5mv , Salas phono and for 1k you never play a cd !
For cartridge look in the world you can find min half price if not 1/3.....
A bit OT, but fast rewind to some seven thousand posts ago and I've stepped upon a trigger for my curiousity.
Reading around, I have already made a nice list of some carts (Denon 103R, Ortofon SPU, Benz ace) and SME IV arm (for an ex.) as possible upgrades from Rega Planar III/Goldring 1012 MM combo. But when it comes to TT I'm clueless. If something springs to your mind in that price range, I'm all ears. Better in PM, I guess.
Hi
today I finished Salas-RIAA-V1102F0. It sounds very nice and detailed, thank you Salas, but at the moment I think I over done it with takman carbon resistors, it is a bit to mellow. I like it but I'll change 47k in the signal path to metal film (PRP). Also I started with 1uF(Ampohm paper in oil) at the output and that took away some very low end. Paralleling another 1uF brought the low end back. I'll avoid PIO as well, and go for the polypropylene at the output (100n is Mundorf Supreme).
The only thing that is a bit of a problem is that I'd like to have more gain. My R2 is 100ohm (Grado black 5mV). I'd like to get closer to the CD output level so I don't need to change the volume so drastically when switching from TT to CD.
Any ideas how to get more gain? Another gain stage? Or changing R2 to 39ohm?
Thank you for this great pre.
Cheers
today I finished Salas-RIAA-V1102F0. It sounds very nice and detailed, thank you Salas, but at the moment I think I over done it with takman carbon resistors, it is a bit to mellow. I like it but I'll change 47k in the signal path to metal film (PRP). Also I started with 1uF(Ampohm paper in oil) at the output and that took away some very low end. Paralleling another 1uF brought the low end back. I'll avoid PIO as well, and go for the polypropylene at the output (100n is Mundorf Supreme).
The only thing that is a bit of a problem is that I'd like to have more gain. My R2 is 100ohm (Grado black 5mV). I'd like to get closer to the CD output level so I don't need to change the volume so drastically when switching from TT to CD.
Any ideas how to get more gain? Another gain stage? Or changing R2 to 39ohm?
Thank you for this great pre.
Cheers
Salas,
can the supply voltage be raised a bit or quite a lot, to allow more headroom in a high output RIAA stage?
If the output voltage is raised to ~600mVac, then that requires a lowish distortion output of ~6Vac for only +20dB of overhead. That is much lower than the usual >30dB overhead allowed and expected in a RIAA stage.
600mVac and +30dB of overhead allowance would require a non clipped output of ~27Vpk.
That would be an almighty RIAA stage. No wonder we see valves/tubes used in some RIAA stages.
can the supply voltage be raised a bit or quite a lot, to allow more headroom in a high output RIAA stage?
If the output voltage is raised to ~600mVac, then that requires a lowish distortion output of ~6Vac for only +20dB of overhead. That is much lower than the usual >30dB overhead allowed and expected in a RIAA stage.
600mVac and +30dB of overhead allowance would require a non clipped output of ~27Vpk.
That would be an almighty RIAA stage. No wonder we see valves/tubes used in some RIAA stages.
We do use rather high B+ choices in our 300mV RMS output builds here, which allows higher value drain resistors, good for easy swing and first stage SNR even. The main restriction of going higher and higher B+ & swing is the distortion rising in those simple JFET cells.
Maybe you remember this alternative MC&PRE combo I had shown once? Its a matter of Rf/Ri on the OPAMP the output gain and 2nd stage won't shake for THD.
Maybe you remember this alternative MC&PRE combo I had shown once? Its a matter of Rf/Ri on the OPAMP the output gain and 2nd stage won't shake for THD.
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I went for 28ohm R2. No distortion, sine wave looks good on o'scope (pre fed with 7mV sine 100Hz). Now I'm much closer to CD out (~1.6V).
I also paralleled 100n with 330n Russian pio, and changed the output cap to 4.7uF. I was short of very low sub frequencies . No hum, buzz rumble etc.
When music is not playing nothing at all comes out of the speakers.
This pre sounds fantastic, thank you very much again Salas. Another improvement and not small at all IMHO, are 10uF PIOs bypassing 10000uF PSU caps, but I'm not sure I'll be able to fit them in the box.
I also paralleled 100n with 330n Russian pio, and changed the output cap to 4.7uF. I was short of very low sub frequencies
. No hum, buzz rumble etc.When music is not playing nothing at all comes out of the speakers.
This pre sounds fantastic, thank you very much again Salas. Another improvement and not small at all IMHO, are 10uF PIOs bypassing 10000uF PSU caps, but I'm not sure I'll be able to fit them in the box.
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Very good. Enjoy.