Hi to everyone! I have discovered this thread just a couple weeks ago, while looking for a proven DIY phono stage, as I have started messing with vinyl and all the staff. I have built the VSPS boards myself, and currently I'm gathering the components. Since it's a little difficult finding the exact ones, I've got some questions about alternatives.
1. Can I use Mundorf bipolars instead of Black Gates for C3? I'm talking about either 4.7uF or 2.2uF
2. I also cannot find silver mica caps for C1,C2. Would Wima MKP or MKS be a good replacement?
3. Last, I consider using the LT1115 as an opamp, however I found comments in the web that it's not suitable for MM cartridges. Is it true?
1. Can I use Mundorf bipolars instead of Black Gates for C3? I'm talking about either 4.7uF or 2.2uF
2. I also cannot find silver mica caps for C1,C2. Would Wima MKP or MKS be a good replacement?
3. Last, I consider using the LT1115 as an opamp, however I found comments in the web that it's not suitable for MM cartridges. Is it true?
Thanks for that arnoldC - there is very little written about the R50 anywhere! But I have heard great things about the zyx range - and most of them are $$$$$.
See I have a very nice dual mono phonoclone ready for this cart (hadn't originally intended to buy that high an output) and was going to get something like a glider etc. - I have a benz L2 on my other deck running into one of RJMs limited edition phonoclones. Then i saw a good deal on a R50 and although a little more than what I was shooting for, if it was as good as the rest of the range, it'd be a keeper. I believe the phonoclone to be at least as good as the likes of a Tom Evans phonostage etc. and is well worthy of a good cart.
The only snag in all this is the output being a bit high - but the internal DC resistance is still only 8R whereas most HOMC tend to be higher, >100R. I know that my L2 is 13R - so the zyx is less than this....
Anyway, sorry for this rambling post. I know its probably off topic at this stage.
So I guess the question still remains for RJM I suppose - is the 0.48mV output too high?
Help!
Fran
See I have a very nice dual mono phonoclone ready for this cart (hadn't originally intended to buy that high an output) and was going to get something like a glider etc. - I have a benz L2 on my other deck running into one of RJMs limited edition phonoclones. Then i saw a good deal on a R50 and although a little more than what I was shooting for, if it was as good as the rest of the range, it'd be a keeper. I believe the phonoclone to be at least as good as the likes of a Tom Evans phonostage etc. and is well worthy of a good cart.
The only snag in all this is the output being a bit high - but the internal DC resistance is still only 8R whereas most HOMC tend to be higher, >100R. I know that my L2 is 13R - so the zyx is less than this....
Anyway, sorry for this rambling post. I know its probably off topic at this stage.
So I guess the question still remains for RJM I suppose - is the 0.48mV output too high?
Help!
Fran
Finally got it all working and together.
Well, after well over a year, I have finally got my phonoclone up and working with a Denon 103 cart on a Project Debut III turntable as the source going to a T-amp and some hand built Transmission line speakers with EJ Jordan JX92S drivers.
It does work, I am glad to say! I do have some questions though...
I think that it sounds really bass shy. I may have to check the boards to see that I have inserted the right capacitors/resistors in the RIAA section (C1 C2 R5 R6). Both channels are affected by this. I find the sound to be very detailed and crisp, but also a bit "honky", ie the upper mids tend to stick out, but as I say the biggest issue is lack of bass.
I will inspect the boards when I got a moment, but any other pointers that you can suggest will be most appreciated!
(I am very excited and happy to get this project almost finished as I travel a lot for work and have incredibly limited time to work on it)
Well, after well over a year, I have finally got my phonoclone up and working with a Denon 103 cart on a Project Debut III turntable as the source going to a T-amp and some hand built Transmission line speakers with EJ Jordan JX92S drivers.
It does work, I am glad to say! I do have some questions though...
I think that it sounds really bass shy. I may have to check the boards to see that I have inserted the right capacitors/resistors in the RIAA section (C1 C2 R5 R6). Both channels are affected by this. I find the sound to be very detailed and crisp, but also a bit "honky", ie the upper mids tend to stick out, but as I say the biggest issue is lack of bass.
I will inspect the boards when I got a moment, but any other pointers that you can suggest will be most appreciated!
(I am very excited and happy to get this project almost finished as I travel a lot for work and have incredibly limited time to work on it)
Bought it but won't have it for a week or so I reckon. Dollar is so weak, almost matches my willpower when it comes to this kind of stuff!
- theya re my wifes eyes rolling there!!
I'll post as soon as it arrives.
Looking arund theres quite a few MCs with that output. I'm hoping it will work OK.
Fran
- theya re my wifes eyes rolling there!!I'll post as soon as it arrives.
Looking arund theres quite a few MCs with that output. I'm hoping it will work OK.
Fran
I got the 0.48mV version. I would have preferred the 0.24mV version but apparently its quite scarce, a special order only. I was buying 2ndhand so there was no way I would ever find one.
To kaban:
I think arnoldc is mixing up the phonoclone and VSPS because of my earlier post about my VSPS. There is no loading in the phonoclone the way there would be in a VSPS.
So its most likely something is wrong in the RIAA. If you look at the circuit on the RJM site, you'd be looking at C1,C2,R5 and R6. You'd want to double check those values - watch out for pF to nF conversion....
Fran
To kaban:
I think arnoldc is mixing up the phonoclone and VSPS because of my earlier post about my VSPS. There is no loading in the phonoclone the way there would be in a VSPS.
So its most likely something is wrong in the RIAA. If you look at the circuit on the RJM site, you'd be looking at C1,C2,R5 and R6. You'd want to double check those values - watch out for pF to nF conversion....
Fran
VSPS
Hi Richard,
Thank you for such an execellent design. Your VSPS has changed my perception for phono entirely. I have been using NAD PP2 with all the mods that I could think of but the sound is still not up to my CD player, mod NAD CD542. I have always advocate that more caps would be better. But in VSPS your recomendation is only 1000uF before regulator and 220uF after. Will the sound improve especially the bass area if I use 470uF or more after regulator. I use all BG std for regulation and BG-N coupling in super E configuration (2 BG-N 4.7uF in each cahnnel). My VSPS is presently on proto board with point to point connection, configured for high gain with R2=300R and R3=2.7K, so there is some traces of buzzing soung at full volume, not that I am listening at full volume. I plan to order the PCB from olimex soon. In your opionion what woud be the optimun set up with regards to capacitor value. Thanks in advance.
Nik S
Hi Richard,
Thank you for such an execellent design. Your VSPS has changed my perception for phono entirely. I have been using NAD PP2 with all the mods that I could think of but the sound is still not up to my CD player, mod NAD CD542. I have always advocate that more caps would be better. But in VSPS your recomendation is only 1000uF before regulator and 220uF after. Will the sound improve especially the bass area if I use 470uF or more after regulator. I use all BG std for regulation and BG-N coupling in super E configuration (2 BG-N 4.7uF in each cahnnel). My VSPS is presently on proto board with point to point connection, configured for high gain with R2=300R and R3=2.7K, so there is some traces of buzzing soung at full volume, not that I am listening at full volume. I plan to order the PCB from olimex soon. In your opionion what woud be the optimun set up with regards to capacitor value. Thanks in advance.
Nik S
OK,
I got the R50 bloom tonight and put it on. Gain is very high and I have a good bit of distortion. I think the gain is set too high, maybe in the first stage and then distorts as a result. I didn't try the cart in another phonostage, but I have a feeling that thats what it is. I have a good bit of hiss/buzz too - again I think this is gain.
So I need to root around a bit and find how to drop the gain. I think I remember something from back in the thread. I'll report progress as I go.
EDIT: So it seems I need to change the value for R2. Standard value is 1.5K. I will increase that by a factor of about 4 or maybe 6 and see what happens. The formula says R2 = 30*Rs where Rs is the cartridge impedance. For the zyx cart that would mean R2=30*8 or 240. So that would mean substituting a lower value resistor to get lower gain. Does this sound right?
Fran
I got the R50 bloom tonight and put it on. Gain is very high and I have a good bit of distortion. I think the gain is set too high, maybe in the first stage and then distorts as a result. I didn't try the cart in another phonostage, but I have a feeling that thats what it is. I have a good bit of hiss/buzz too - again I think this is gain.
So I need to root around a bit and find how to drop the gain. I think I remember something from back in the thread. I'll report progress as I go.
EDIT: So it seems I need to change the value for R2. Standard value is 1.5K. I will increase that by a factor of about 4 or maybe 6 and see what happens. The formula says R2 = 30*Rs where Rs is the cartridge impedance. For the zyx cart that would mean R2=30*8 or 240. So that would mean substituting a lower value resistor to get lower gain. Does this sound right?
Fran
OK,
I think I have this sorted fairly quick!
I reduced R2 to either 370R or 320R (my head is like a sieve tonight, I can't remember which I put in!) and all the distortion is gone. Sounds sweet again and all is well.
Nagging doubt: RJM says not to go below 500R if you can avoid it, so I have broken that rule. However it seems to be working AOK.
You might be asking why I didn't go with VSPS for a cart with that output. Well, first the output is kinda in the middle, not very high for a HOMC, but yet higher than a standard LOMC. Also, I just have this thing that I think the phonoclone is a better phonostage than the VSPS. I can't prove that, and its even unfair of me to say it because I have never used comparable quality MM carts>>VSPS as I have done with MCs into the phonoclone, so I'm not comparing like with like.
Anyway, all is well now.
Other builders/zyx owners take note of the gain adjustment.
Fran
I think I have this sorted fairly quick!
I reduced R2 to either 370R or 320R (my head is like a sieve tonight, I can't remember which I put in!) and all the distortion is gone. Sounds sweet again and all is well.
Nagging doubt: RJM says not to go below 500R if you can avoid it, so I have broken that rule. However it seems to be working AOK.
You might be asking why I didn't go with VSPS for a cart with that output. Well, first the output is kinda in the middle, not very high for a HOMC, but yet higher than a standard LOMC. Also, I just have this thing that I think the phonoclone is a better phonostage than the VSPS. I can't prove that, and its even unfair of me to say it because I have never used comparable quality MM carts>>VSPS as I have done with MCs into the phonoclone, so I'm not comparing like with like.
Anyway, all is well now.
Other builders/zyx owners take note of the gain adjustment.
Fran