Hi RJM (and thanks for the response!)
I have bought a Denon DL-103 cartridge as an upgrade - I assumed the phonoclone was a good preamp for this? I am basically making the standard phonoclone as suggested on your website.
After this I may play with the configuration a little... actually do I need to make any adjustments to the standard component values to match it to a DL-103? And I assume the NE5534 is ok to just drop in?
Again, thanks...
I have bought a Denon DL-103 cartridge as an upgrade - I assumed the phonoclone was a good preamp for this? I am basically making the standard phonoclone as suggested on your website.
After this I may play with the configuration a little... actually do I need to make any adjustments to the standard component values to match it to a DL-103? And I assume the NE5534 is ok to just drop in?
Again, thanks...
Hi rjm,
first of all, many thanks for your schematics and the enlightning articles on them.
I am planning a vsps right now. As I have only dual opamps at hand right now (opa2134) and I want to build a dual mono version, I thought about adding a buffer and/or additional gain stage to the vsps. E.g. build a vsps with a gain of 40dB and a second stage with a gain of 2 which also drives the cables. This way, the riaa network would be unaffected by the input imp of the following stage.
Would it be an advantage to set this gain- stage before the riaa- stage?
Best regards
Floric
first of all, many thanks for your schematics and the enlightning articles on them.
I am planning a vsps right now. As I have only dual opamps at hand right now (opa2134) and I want to build a dual mono version, I thought about adding a buffer and/or additional gain stage to the vsps. E.g. build a vsps with a gain of 40dB and a second stage with a gain of 2 which also drives the cables. This way, the riaa network would be unaffected by the input imp of the following stage.
Would it be an advantage to set this gain- stage before the riaa- stage?
Best regards
Floric
I think not. I mean there is a school of thought that says split the gain over two or more stages to give each individual opamp less work to do. You'll find several two-stage MM phono stage circuits floating around the net, with passive, active, or split passive/active eq. I always though of the VSPS as a single stage design, the virtue of doing everything in one shot was the simplicity of layout/grounding and low parts count.
You could put a gain stage in front. Sort of a noninverting pseudo Phonoclone if you will. I question the need with a MM cartridge, however. I suspect that once you go and draw up the circuit and fill in the parts values you'll some difficulties arise, cheifly with headroom and impedances. As an exercise why not draw it up and post here and we'll all have a look.
/rjm
You could put a gain stage in front. Sort of a noninverting pseudo Phonoclone if you will. I question the need with a MM cartridge, however. I suspect that once you go and draw up the circuit and fill in the parts values you'll some difficulties arise, cheifly with headroom and impedances. As an exercise why not draw it up and post here and we'll all have a look.
/rjm
Hi,
thanks for your answer. The idea was to try out the vsps without the need to buy new parts. I have them all, except for the single opamps but there are plenty of dual ones in my drawler: opa2134,lm4562, ne5532, lt1037 (o.k. this one is not unity gain stable). So I thought about adding a simple buffer after the vsps to - not only because I use a "passive pre" at the moment. The next idea was to add some gain.
That's not that difficult, if you look at a simple buffer that will be added between r6 and c3.
But I think, if the impedances of the following stages are no problem, I will look for single ops.
Best Regards
thanks for your answer. The idea was to try out the vsps without the need to buy new parts. I have them all, except for the single opamps but there are plenty of dual ones in my drawler: opa2134,lm4562, ne5532, lt1037 (o.k. this one is not unity gain stable). So I thought about adding a simple buffer after the vsps to - not only because I use a "passive pre" at the moment. The next idea was to add some gain.
That's not that difficult, if you look at a simple buffer that will be added between r6 and c3.
But I think, if the impedances of the following stages are no problem, I will look for single ops.
Best Regards
Sorry, I misunderstood your ealier post somewhat. I see you intended to put a buffer on the output. That makes more sense. What you are doing in essence is tacking on a preamp. You could easily add a volume control and switching in between the two stages, for example, and have a proper little preamplifier. A low gain opamp as the output stage should in theory be able to better drive long cables or difficult loads. The VSPS part is unmodified.
So, yeah, your plan sounds fine to me. A bit pointless perhaps, if you dont build in the preamp functionality since its purely speculative that the extra stage will significantly improve the sound, but if you are happy to come up with a layout for your circuit there's nothing technical stopping it from working out nicely.
Me, I'd go and add 2-3 line inputs, transplant the attenuator from the passive pre, and add a headphone jack. Maybe increase the gain of the output stage to 5x. Voila preamp!
/R
So, yeah, your plan sounds fine to me. A bit pointless perhaps, if you dont build in the preamp functionality since its purely speculative that the extra stage will significantly improve the sound, but if you are happy to come up with a layout for your circuit there's nothing technical stopping it from working out nicely.
Me, I'd go and add 2-3 line inputs, transplant the attenuator from the passive pre, and add a headphone jack. Maybe increase the gain of the output stage to 5x. Voila preamp!
/R
O.K. now I understand your comments, the gain stage before the vsps was only an option. The main idea was to use dual opamps in a dual-mono design and to keep the phono-pre as flexible as possible. With a Buffer in the second half of the dual opamp, the number of parts is not really increased.
I am thinking of a preamp, but I think, I would do it another way.
One option with the idea would be an output stage for the vsps with a variable gain like Linkwitz circuit A to have the possibility for a slight volume adjustment before the preamp.
I am thinking of a preamp, but I think, I would do it another way.
One option with the idea would be an output stage for the vsps with a variable gain like Linkwitz circuit A to have the possibility for a slight volume adjustment before the preamp.
I've started working on a VSPS and have made the PCBs. I used photo paper and an iron to transfer the layout to the board. The final result isn't as nice as an Olimex board, but it is good enough for me. Now I'm just waiting for the parts to arrive.
Thanks for putting so much effort into this project.
pete
Thanks for putting so much effort into this project.
pete
Attachments
In my view, you lose nothing. The additional 2-3 pF of capacitance and whatever inductance there is in the extra 5 mm of metal is trivial at the frequencies these circuits operate at.
So do whatever makes you happiest: sockets for messing around, or unsocketed for a sense of (probably unjustified) security.
![perfectsocket[1].jpg](/community/data/attachments/65/65893-7cfaa125bc5756bb4119f6b94d727ebc.jpg)
Nice looking socket
Mr. Daniel,
Who makes that socket?
I went to SAYAL and found it to be RATHER confusing. Would you be willing to say how it is designated?
Would you be willing to suggest what rectifier diodes you would recommend for a phono amp?
With all of the talk about the LM4562's single counterpart LME49710, could this be a good choice for PHONOCLONE? I am going to try them (put them on order). It seems like it should be safe to use. Nonetheless I would appreciate the opinion of rjm as to the advisability of using this (especially) as a first stage. NATIONAL's spec sheet say typically .05mV input offset voltage.
Thanks to you both for the advice. Nothing like convenience without (much) ciompromise.
Mr. Daniel,
Who makes that socket?
I went to SAYAL and found it to be RATHER confusing. Would you be willing to say how it is designated?
Would you be willing to suggest what rectifier diodes you would recommend for a phono amp?
With all of the talk about the LM4562's single counterpart LME49710, could this be a good choice for PHONOCLONE? I am going to try them (put them on order). It seems like it should be safe to use. Nonetheless I would appreciate the opinion of rjm as to the advisability of using this (especially) as a first stage. NATIONAL's spec sheet say typically .05mV input offset voltage.
Thanks to you both for the advice. Nothing like convenience without (much) ciompromise.
I buy it directly from one of their outlet stores, I'm not sure who makes them.
Almost everywhere I use MUR860 rectifiers and usually they work fine.
I recently tried LM4562 in a DAC I/V stage and I like it, not sure however how it might perform with phono stage. I used OPA627 in VSPS and OPA627/637 in a clone.
Almost everywhere I use MUR860 rectifiers and usually they work fine.
I recently tried LM4562 in a DAC I/V stage and I like it, not sure however how it might perform with phono stage. I used OPA627 in VSPS and OPA627/637 in a clone.
Attachments
I had a look at the LM4562 data sheet. Pages and pages of THD charts mostly. The basic specs look very, very similar to the OP37 however.
Unfortunately the OP37 doesn't seem to like the phonoclone, at least not those of the people who've tried the substitute.
So in principle yes it should work but you may have a bit of trouble accomodating the 55Mhz gain-bandwidth product, which will give very high circuit bandwidths up in the Megahertz. Extra bypassing and so forth may be required.
/R
Unfortunately the OP37 doesn't seem to like the phonoclone, at least not those of the people who've tried the substitute.
So in principle yes it should work but you may have a bit of trouble accomodating the 55Mhz gain-bandwidth product, which will give very high circuit bandwidths up in the Megahertz. Extra bypassing and so forth may be required.
/R
Input offset voltage question
I think the oscillation problems can be fixed with the LM4562 and it's single counterpart the LME49710, which is what I am going to try.
My concern: where is the danger point with inout offset volatge? The 49710 spec sheet says typically .05mV. Is this O.K.? This is much lower than the 4562 specifications.
I do not want to burn up expensive coils. I would greatly appreciate the benefit of the knowledge of those who know far more than I.
Does this device have more problems with the first stage or the second stage? NATIONAL shows a feedback loop RIAA configuarion within the spec sheet, so is the first stage the tricky one? Does extra compensation always work?
I think the oscillation problems can be fixed with the LM4562 and it's single counterpart the LME49710, which is what I am going to try.
My concern: where is the danger point with inout offset volatge? The 49710 spec sheet says typically .05mV. Is this O.K.? This is much lower than the 4562 specifications.
I do not want to burn up expensive coils. I would greatly appreciate the benefit of the knowledge of those who know far more than I.
Does this device have more problems with the first stage or the second stage? NATIONAL shows a feedback loop RIAA configuarion within the spec sheet, so is the first stage the tricky one? Does extra compensation always work?
Given the DC resistance of your cartridge, R, the heat is (V^2)/R.
One volt is unlikely to kill it. More than that likely will. An input offset voltage of 50uV is trivial, and similar to the OP27. Nothing to worry about.
*****
attached: Eagle brd and sch files for the phonoclone mini version 26i. I posted a similar board with RC filters and LM7x12s a while back. The most significant change is I updated my lbr files to have resistors and capacitors with wider pads and larger drill holes. In software jargon this version is RC2. Good to go, though I might have forgotton to dot an i somewhere.
/R
One volt is unlikely to kill it. More than that likely will. An input offset voltage of 50uV is trivial, and similar to the OP27. Nothing to worry about.
*****
attached: Eagle brd and sch files for the phonoclone mini version 26i. I posted a similar board with RC filters and LM7x12s a while back. The most significant change is I updated my lbr files to have resistors and capacitors with wider pads and larger drill holes. In software jargon this version is RC2. Good to go, though I might have forgotton to dot an i somewhere.
/R
Hi,
I'm using a thorens 321--sme 3009---dl 103 R with a Jolida jd-9 phonostage, would the phonoclone be an improvement? the jolida jd-9 performs on the level of a musical fidelity xLPS (v2)
I'm a DIy beginner, I ordered some parts to modify my trends ta-10 last week.... Could I do this? And is it possible to use a simple ready-made PS?
Another question, how much will the total cost be? 100 -200 dollars?
Thanks, since this thread is so long , I don't feel like reading trough it if there's no use for me doing it ( Read the first 10 pages)
Robert
I'm using a thorens 321--sme 3009---dl 103 R with a Jolida jd-9 phonostage, would the phonoclone be an improvement? the jolida jd-9 performs on the level of a musical fidelity xLPS (v2)
I'm a DIy beginner, I ordered some parts to modify my trends ta-10 last week.... Could I do this? And is it possible to use a simple ready-made PS?
Another question, how much will the total cost be? 100 -200 dollars?
Thanks, since this thread is so long , I don't feel like reading trough it if there's no use for me doing it ( Read the first 10 pages)
Robert