I'm totally newbie, this will be my first mod ever. This is the inside of the phono stage:Google Image Result for http://www.ippinkan.com/musical_fidelity/v-series/V-LPS_circuit800.jpg
Okay, I willl concentrate my effort for now on:
Swapping the powersupply
changing the fist stage op-amps and the second stage
changing all the caps to panasonic FC
I have a couple of question:
-I see three IC: IC1 (5532dd jrc 0024b), ic 301(NE5534AP) and IC 201 (NE5534AP). Which is which; IC1 is the second stage and IC301 and IC201 is the first stage? or is it the contrary? Should I need to replace all three with LME49710? Also I heard that the LME49710 is a good op-amp, but feel free to suggest me something that would probably be better.
-I need to replace all the caps. All the black one are jamicon and I change ALL of them? to panasonic FC, all with the same value, or I match the same value?
I seems to have 2 different jamicon caps: 100 uf 16V so I replace those with those:Wholesale taobao Panasonic FC 100UF/16V high-speed low-impedance capacitor
and the 16V 1000uf with those Panasonic FC 1000uF 16V :: Panasonic FC :: Panasonic :: Electrolytics :: Capacitors :: Passive Components :: Electronic Parts :: Banzai Music
Also, can I use something better then those panasonic ones, I could pay much more if I ccan see a difference...
Okay, I willl concentrate my effort for now on:
Swapping the powersupply
changing the fist stage op-amps and the second stage
changing all the caps to panasonic FC
I have a couple of question:
-I see three IC: IC1 (5532dd jrc 0024b), ic 301(NE5534AP) and IC 201 (NE5534AP). Which is which; IC1 is the second stage and IC301 and IC201 is the first stage? or is it the contrary? Should I need to replace all three with LME49710? Also I heard that the LME49710 is a good op-amp, but feel free to suggest me something that would probably be better.
-I need to replace all the caps. All the black one are jamicon and I change ALL of them? to panasonic FC, all with the same value, or I match the same value?
I seems to have 2 different jamicon caps: 100 uf 16V so I replace those with those:Wholesale taobao Panasonic FC 100UF/16V high-speed low-impedance capacitor
and the 16V 1000uf with those Panasonic FC 1000uF 16V :: Panasonic FC :: Panasonic :: Electrolytics :: Capacitors :: Passive Components :: Electronic Parts :: Banzai Music
Also, can I use something better then those panasonic ones, I could pay much more if I ccan see a difference...
If it is of any age then the electrolytics will need changing.
Care needs to be taken with faster op-amps as you could end up with instability.
Care needs to be taken with faster op-amps as you could end up with instability.
It's hard to say without the schematic.But if there is a NE5534AP then I would be carefull with replacing it because it's not fully internally compensated and probably uses some additional compensation.So if you replace it with another opamp then it will be overcompensated.
okay so I guess that the two ne5534ap are the first opamp stages. I will change the second stage op-amp
I see there 5 IC. 4 are for the phono stage and the fifth probably for power supply.What brand are IC 202 and 302? I assume they are also NE5534.
yes, ic 202 and 302 are ne5534... I guess those don't afffect the sound and shouldn't be changed?
Is there a reason why you are making the mods?
Are you unhappy with the sound of the preamp?
What are you trying to accomplish?
Are you unhappy with the sound of the preamp?
What are you trying to accomplish?
I would not replace them at all, but if you want do it then I can recomend LME49710 or something similar.However there is some risk that it will oscillate or something like this.
In general for phono stage you need an opamp with low noise, other specs such as slew rate and bandwidth are not very important here. Altough bandwidth can be also important because they have high gain and the more gain you need the less high frequency is amplified.But this is two stage design and this should be not as critical as with only one stage.
In general for phono stage you need an opamp with low noise, other specs such as slew rate and bandwidth are not very important here. Altough bandwidth can be also important because they have high gain and the more gain you need the less high frequency is amplified.But this is two stage design and this should be not as critical as with only one stage.
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Hi,
The single NE5534 is lower noise than the NE5532 dual as it essentially
uses both input sets of transistors of a 5532 die. Its compensated for
gains > 3, whilst the dual is unity gain stable.
(single has compensation connections, the dual doesn't.)
They are very high value IC op-amps, which is why they are used so much.
At a cost you can change them but optimum choice requires understanding
of the stage gain and required compensation for optimum performance.
It is possible to replace a dual (unity gain stable) with dual singles (variable
compensation) if your after using the optimum compensation possible.
rgds, sreten.
The single NE5534 is lower noise than the NE5532 dual as it essentially
uses both input sets of transistors of a 5532 die. Its compensated for
gains > 3, whilst the dual is unity gain stable.
(single has compensation connections, the dual doesn't.)
They are very high value IC op-amps, which is why they are used so much.
At a cost you can change them but optimum choice requires understanding
of the stage gain and required compensation for optimum performance.
It is possible to replace a dual (unity gain stable) with dual singles (variable
compensation) if your after using the optimum compensation possible.
rgds, sreten.
I'm curious why you want to modify a brand new phono stage, are you having problems with it, don't like the sonics, or do you just have the "want to smell solder resin" bug. Just wondering.
Mike
Mike
On the hazards of IC swapping (and this was an NE5534),
http://www.diyaudio.com/forums/anal...u-have-checked-see-its-stable-havent-you.html
http://www.diyaudio.com/forums/anal...u-have-checked-see-its-stable-havent-you.html
Hi,
Do you at least have some reasonably solid electronics background? You can solder well?
Proceeding without schematic can be problematic, especially if someone is using 5534 Chips, as these can be used in ways that are, shall way say unusual and interesting, so circuits may not behave as expectecd.
Something that has been retained by MF for the principle design (but with small differences) for their Phonostages was found in the MF A-1. You can the circuit here:
Musical Fidelity A1 - Technical
Looking at the V-LPS picture I think the circuit may still be similar to that original one in the A1. It is actually a quite smart piece of engineering.
This is 12V DC, there seems to be quite a bit extra going on there.
Could be causing problems, without a full circuit diagram I would leave the 5534.
I doubt this will help much.
For electrolytic capacitors the best choice are Elna Silmic. Subjectively I find them to offer appreciable improvements in smoothness of sound, without loosing detail, objectively they have lower measured distortion (a lot lower) than common garden ones.
Further, there are many little red Mylar Cap's (not sure what the little round blue ones are, possibly mylars too), which will have a significant impact on sound quality (greater than all the others).
It will be well worth to replace the ones in the Feedback/EQ circuit with polystyrene ones (try finding ones that enclose the capacitors in a plastic box), the others may be at least plastic cased Wima or similar.
In the linked Photo I see five...
IC 201/301 would be the output/EQ stage of the Phono stage.
IC1 looks like Powersupply.
IC 202/302 Appear to be some AD types, but I cannot tell for sure which ones.
Definitly NOT. The 5532 is a DUAL Op-Amp, the LME49710 is a single.
It is okay, there are many worse, many better ones. It depends a lot on the precise application. One needs to know the circuit, derive the requirements and then select the best choice, there is no "universally good" device here.
I doubt the Panasonic FC will be a major step up. As a rule, I prefer to use Elna Silmic for Audio, usually the biggest value that can be fitted/found.
However, in some cases it may better using a lower value film cap, in other cases using a very large value ordinary grade capacitor may be best.
One really needs to know and understand the circuit to be able to determine what is needed where.
If in doubt a 1:1 (same value, same voltage rating) with Elna Silmic is absolutely safe and can produce quite notable improvements.
Ciao T
Do you at least have some reasonably solid electronics background? You can solder well?
Proceeding without schematic can be problematic, especially if someone is using 5534 Chips, as these can be used in ways that are, shall way say unusual and interesting, so circuits may not behave as expectecd.
Something that has been retained by MF for the principle design (but with small differences) for their Phonostages was found in the MF A-1. You can the circuit here:
Musical Fidelity A1 - Technical
Looking at the V-LPS picture I think the circuit may still be similar to that original one in the A1. It is actually a quite smart piece of engineering.
This is 12V DC, there seems to be quite a bit extra going on there.
Could be causing problems, without a full circuit diagram I would leave the 5534.
I doubt this will help much.
For electrolytic capacitors the best choice are Elna Silmic. Subjectively I find them to offer appreciable improvements in smoothness of sound, without loosing detail, objectively they have lower measured distortion (a lot lower) than common garden ones.
Further, there are many little red Mylar Cap's (not sure what the little round blue ones are, possibly mylars too), which will have a significant impact on sound quality (greater than all the others).
It will be well worth to replace the ones in the Feedback/EQ circuit with polystyrene ones (try finding ones that enclose the capacitors in a plastic box), the others may be at least plastic cased Wima or similar.
In the linked Photo I see five...
IC 201/301 would be the output/EQ stage of the Phono stage.
IC1 looks like Powersupply.
IC 202/302 Appear to be some AD types, but I cannot tell for sure which ones.
Definitly NOT. The 5532 is a DUAL Op-Amp, the LME49710 is a single.
It is okay, there are many worse, many better ones. It depends a lot on the precise application. One needs to know the circuit, derive the requirements and then select the best choice, there is no "universally good" device here.
I doubt the Panasonic FC will be a major step up. As a rule, I prefer to use Elna Silmic for Audio, usually the biggest value that can be fitted/found.
However, in some cases it may better using a lower value film cap, in other cases using a very large value ordinary grade capacitor may be best.
One really needs to know and understand the circuit to be able to determine what is needed where.
If in doubt a 1:1 (same value, same voltage rating) with Elna Silmic is absolutely safe and can produce quite notable improvements.
Ciao T
thanks a lot!
I plan on modifying it because some people on the net have done it and all said how better their phono sound afterwards.
I replaced the powersupply yesterday and use a regulated psu.
I just notice that the picture I send you of the inside of the v-lps is not exactly what I have! their must have been different versions and I can' find mine. I'm positive, I don't have 5 IC, only 3.
Yes I know how to solder and just want to give it a try, see if I can make it sound better, its fun thats all, but I need your help 🙂
Okay so I understand that I cannot replace 5532 with a lme49571, what do you guys suggest as a great DUAL op-amp that would fit here.
I plan on modifying it because some people on the net have done it and all said how better their phono sound afterwards.
I replaced the powersupply yesterday and use a regulated psu.
I just notice that the picture I send you of the inside of the v-lps is not exactly what I have! their must have been different versions and I can' find mine. I'm positive, I don't have 5 IC, only 3.
Yes I know how to solder and just want to give it a try, see if I can make it sound better, its fun thats all, but I need your help 🙂
Okay so I understand that I cannot replace 5532 with a lme49571, what do you guys suggest as a great DUAL op-amp that would fit here.
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Hi,
It would be good if you could snap a picture.
If it only has 3 IC's, two 5534 and one 5532 it is almost 100% certain the same circuit as in the A1 I referenced earlier.
Then I would leave the 5532, the two 5534 could be replaced, maybe not the Nat Semi LME part, but your call. I would probably use Burr Brown OPA627 myself.
If we can confirm that the schematic basically matches A1, there are other things to do... And we can be more specific which cap's should be Silmic and which can stay ordinary (saves money) and which may better be Film types.
Also check which transistors are used in the first stage.
Ciao T
It would be good if you could snap a picture.
If it only has 3 IC's, two 5534 and one 5532 it is almost 100% certain the same circuit as in the A1 I referenced earlier.
Then I would leave the 5532, the two 5534 could be replaced, maybe not the Nat Semi LME part, but your call. I would probably use Burr Brown OPA627 myself.
If we can confirm that the schematic basically matches A1, there are other things to do... And we can be more specific which cap's should be Silmic and which can stay ordinary (saves money) and which may better be Film types.
Also check which transistors are used in the first stage.
Ciao T
wow thats great news, I was about to buy the silmic caps for all the caps, I'll wait.
I'll take pictures today. I have contacted musical fidelity for a schematic
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how can we confirm if its the same circuit as the A 1?
Also I have been reading on the AD825 op-amp, would it fit in my circuit? the opa627 is quite expensive, but if its worth it, I'd go with the most expensive option... I have also read in here that op-amps is not where the big difference in the sound will occur, but much more in the caps... Should I even change my op-amps?
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