Battery power supply?
Hi, just getting back into vinyl after over 10 years of CD. I am considering building the Phonoclone for my Denon DL103.
Having built a couple of op-amp headphone amps successfuly using battery power supplies I am wondering if the phonoclone would work well this way. I know it can be done but any opinion as to effect on sound quality. I would be using 16 AA cells to produce a +/-12v split supply. Possibly use some small caps right next to the ICs but otherwise no ps smoothing caps.
Also does the output coupling cap need to be so large? Would 2uF be adequate as more choice exists for reasonable sized quality caps at that size.
Thanks in advance,
Chris
Hi, just getting back into vinyl after over 10 years of CD. I am considering building the Phonoclone for my Denon DL103.
Having built a couple of op-amp headphone amps successfuly using battery power supplies I am wondering if the phonoclone would work well this way. I know it can be done but any opinion as to effect on sound quality. I would be using 16 AA cells to produce a +/-12v split supply. Possibly use some small caps right next to the ICs but otherwise no ps smoothing caps.
Also does the output coupling cap need to be so large? Would 2uF be adequate as more choice exists for reasonable sized quality caps at that size.
Thanks in advance,
Chris
Finished Phonoclone, Sounds very good
Now I finished my phonoclone successfully. I had some problems with hum and rewired the ground a few times. Now its fairly free from hum - only a very silent hum while turning the volume to the right end. Noise is not an issue even if its present at high volume levels. I used generic components for all parts, regular elko caps, WIMA MKP-10 RIAA-Caps, metal film resistors 0,1%, no sophisticated power supply regulation. In fact I used a 2x12V lead acid battery and a desktop power supply 2x12V/25W - I couldnt find a difference yet - but the circuit is not warmed up completely. Noise has some hash, even from the lead acids battery. So its not implied by the power supply. I used another PCB (half euro size) for both channels. First impression of the first 10 records: it sounds fine using my shelter 901 compared to my cyrus phono stage and my lehmann black cube SE (and far beyond my kitchens denon PM720 phono input).
Next steps: Build the whole thing a second time, using sophisticated material like WIMA FKP-2, Black Gate, Mundorf Audio Caps and compare the sound.
pictures here:
Now I finished my phonoclone successfully. I had some problems with hum and rewired the ground a few times. Now its fairly free from hum - only a very silent hum while turning the volume to the right end. Noise is not an issue even if its present at high volume levels. I used generic components for all parts, regular elko caps, WIMA MKP-10 RIAA-Caps, metal film resistors 0,1%, no sophisticated power supply regulation. In fact I used a 2x12V lead acid battery and a desktop power supply 2x12V/25W - I couldnt find a difference yet - but the circuit is not warmed up completely. Noise has some hash, even from the lead acids battery. So its not implied by the power supply. I used another PCB (half euro size) for both channels. First impression of the first 10 records: it sounds fine using my shelter 901 compared to my cyrus phono stage and my lehmann black cube SE (and far beyond my kitchens denon PM720 phono input).
Next steps: Build the whole thing a second time, using sophisticated material like WIMA FKP-2, Black Gate, Mundorf Audio Caps and compare the sound.
pictures here:
Attachments
Batch Order 3
Announcement:
The deadline to order VSPS and Phonoclone PCBs is Sunday, Sept 11th. I must receive your payment before then. Just so you know, Order 4 wont be until January next year, though I'll get a couple of extra boards done this time for the "emergency reserves"..
Details at the ordering page, here.
-rjm
Announcement:
The deadline to order VSPS and Phonoclone PCBs is Sunday, Sept 11th. I must receive your payment before then. Just so you know, Order 4 wont be until January next year, though I'll get a couple of extra boards done this time for the "emergency reserves"..
Details at the ordering page, here.
-rjm
Member
Joined 2004
Member
Joined 2004
Member
Joined 2004
Improvements/Experiences Phonoclone
Now I finished my second version of the phonoclone, using some voodoo material like black gates etc. I made some observations while listening to both phonoclones.
1. The difference between the black gate board and the generic one is not that much. Something like very very little personal taste. There are more crucial improvements.
2. Improvement 1: Do not use this capacitor (220pF) between pin 2 and 3 of the OP1. Even if this will solve the problem of radio transmissions in your phono line it will introduce a BIG DC Offset in the whole cuircuit AND it sounds worse than without the cap. The DC offset results in a 14V DC at the output of OP2 (in a +-15V-Supply). Yes -the DC is filtered by output coupling cap, but it seems to affect the sound. Normally without the 220pf cap you have a DC at OP2 of 0..50mV !
3. Improvement 2: If there are problems with radio transmissions (I had this), use an OP27 in the first stage. It went away and had the effect of a 3rd improvement:
4. Improvement 3: The OP27 sounds much better in the 1st stage than the OP37. Dont know why but it's a fact. I use OP27 only now (I do not need the 90dB gain version). (There is another preference to use OP27G than the OP27E-Series or the Burr-Brown OPA227, which I tried, but thats personal taste)
5. Improvement 4: Instead the 78**/79** regulation use a LM3*7 regulation. The 78**/79** regulation causes some hash in the noise of the preamp. This hash went away in a LM3*7 regulation. (Maybe the 78**/79** regulation depends on the exact match of the regulator chips - I couldnt find any chips in a set of 20 which could by matched to 0,2V. Something like +14,6V -14,8V was used. Tolerance was from 14,25V to 15,8V for 7815 or 7915) Now I use variable regulation with LM3*7 an +10,01V -10,02V see Improvement 5)
6. Improvement 5: I use both phonoclones with a supply of +-10V instead of +-15V or +-12V. It is less noisier (but have not measured it), Maybe it depends on the whole power supply configuration and the use of a +-17V transformator.
It is a fine preamp now, far beyond the sound of my lehmann black gate SE, SUPA phono stage, cyrus two integrated phonostage (and the denon integrated phono stage). OK, you can configure nothing ...
So far, bspx
Next steps: Because I do not need the gain of the phonoclone (Shelter 901 has 0,4mV), I will try the VSPS ultra and compare the sound to the phonoclone. Any experiences in both out there already ?
Now I finished my second version of the phonoclone, using some voodoo material like black gates etc. I made some observations while listening to both phonoclones.
1. The difference between the black gate board and the generic one is not that much. Something like very very little personal taste. There are more crucial improvements.
2. Improvement 1: Do not use this capacitor (220pF) between pin 2 and 3 of the OP1. Even if this will solve the problem of radio transmissions in your phono line it will introduce a BIG DC Offset in the whole cuircuit AND it sounds worse than without the cap. The DC offset results in a 14V DC at the output of OP2 (in a +-15V-Supply). Yes -the DC is filtered by output coupling cap, but it seems to affect the sound. Normally without the 220pf cap you have a DC at OP2 of 0..50mV !
3. Improvement 2: If there are problems with radio transmissions (I had this), use an OP27 in the first stage. It went away and had the effect of a 3rd improvement:
4. Improvement 3: The OP27 sounds much better in the 1st stage than the OP37. Dont know why but it's a fact. I use OP27 only now (I do not need the 90dB gain version). (There is another preference to use OP27G than the OP27E-Series or the Burr-Brown OPA227, which I tried, but thats personal taste)
5. Improvement 4: Instead the 78**/79** regulation use a LM3*7 regulation. The 78**/79** regulation causes some hash in the noise of the preamp. This hash went away in a LM3*7 regulation. (Maybe the 78**/79** regulation depends on the exact match of the regulator chips - I couldnt find any chips in a set of 20 which could by matched to 0,2V. Something like +14,6V -14,8V was used. Tolerance was from 14,25V to 15,8V for 7815 or 7915) Now I use variable regulation with LM3*7 an +10,01V -10,02V see Improvement 5)
6. Improvement 5: I use both phonoclones with a supply of +-10V instead of +-15V or +-12V. It is less noisier (but have not measured it), Maybe it depends on the whole power supply configuration and the use of a +-17V transformator.
It is a fine preamp now, far beyond the sound of my lehmann black gate SE, SUPA phono stage, cyrus two integrated phonostage (and the denon integrated phono stage). OK, you can configure nothing ...
So far, bspx
Next steps: Because I do not need the gain of the phonoclone (Shelter 901 has 0,4mV), I will try the VSPS ultra and compare the sound to the phonoclone. Any experiences in both out there already ?
Re: Improvements/Experiences Phonoclone
Thanks very much for your comments. It would be great if you could provide further info on the following points:
Do you mean as the output coupling cap, or for the bypass/filter caps?
Are you comparing LM3*7 in both cases, or was the 12V and 15V with 79xx/78xx?
-rjm
Thanks very much for your comments. It would be great if you could provide further info on the following points:
Do you mean as the output coupling cap, or for the bypass/filter caps?
Are you comparing LM3*7 in both cases, or was the 12V and 15V with 79xx/78xx?
-rjm
comments to improvements of phonoclone
At first one thing I forgot - I'd like to thank RJM for excellent engineering (re-engineering) and documentation of the phonoclone and vsps ultra projects !
Some comments:
1. I used the black gates as coupling caps and some ELNA SILMIC (brown ones) as bypass caps near the OPs (220µ). I used generic
caps (470µ) as filter caps. One interesting point: I couldnt get the first stage (with OP27E, OP37G, OP37E) stable (the stage worked as a buzzer at 5KHz) without some extra bypass caps of 100n polypro in parallel. No problems with stability and the OP27G.
2. Regulation was THE issue for the phonoclone and sound improvements. I used regulation chips off-board and bypassing on-board near the OPs. Because I used some off-board regulation unit I could do some experimentals:
- 7815/7915, 7812/7912, 3*7 at 15V, 3*7 at 12V, 3*7 at 10V, Akku-Supply (2x12V lead)
I used a variable supply for the 3*7 regulation providing the most flexibilty. The sound and noise improved in the upper mentioned descending order. Akku-Supply is ok but I do not prefer this solution yet because of the absence of some effecient charging device.
So far, BSPX
At first one thing I forgot - I'd like to thank RJM for excellent engineering (re-engineering) and documentation of the phonoclone and vsps ultra projects !
Some comments:
1. I used the black gates as coupling caps and some ELNA SILMIC (brown ones) as bypass caps near the OPs (220µ). I used generic
caps (470µ) as filter caps. One interesting point: I couldnt get the first stage (with OP27E, OP37G, OP37E) stable (the stage worked as a buzzer at 5KHz) without some extra bypass caps of 100n polypro in parallel. No problems with stability and the OP27G.
2. Regulation was THE issue for the phonoclone and sound improvements. I used regulation chips off-board and bypassing on-board near the OPs. Because I used some off-board regulation unit I could do some experimentals:
- 7815/7915, 7812/7912, 3*7 at 15V, 3*7 at 12V, 3*7 at 10V, Akku-Supply (2x12V lead)
I used a variable supply for the 3*7 regulation providing the most flexibilty. The sound and noise improved in the upper mentioned descending order. Akku-Supply is ok but I do not prefer this solution yet because of the absence of some effecient charging device.
So far, BSPX
One short question to VSPS ultra
Before starting the VSPS ultra project I got some short questions:
Does the invertion (inverting topology) has an impact on the following amplification stages ? Do I listen at the end of the chain a "reverse" phase like a switch of the speaker cables ? Does switching the speaker cables solve this problem ?
Thank you for responses, BSPX
Before starting the VSPS ultra project I got some short questions:
Does the invertion (inverting topology) has an impact on the following amplification stages ? Do I listen at the end of the chain a "reverse" phase like a switch of the speaker cables ? Does switching the speaker cables solve this problem ?
Thank you for responses, BSPX
That works too...
By the way, despite a 20% reserve on the last batch order, all the extras have been snapped up before the physical boards even reached my hands. No more VSPS, and one ... one lonely Phonoclone left. So much for my "reserve stock".
In a related note, Black Gate N 50V/4.7uF caps appear to be back in stock at the Osaka stores.
-R
By the way, despite a 20% reserve on the last batch order, all the extras have been snapped up before the physical boards even reached my hands. No more VSPS, and one ... one lonely Phonoclone left. So much for my "reserve stock".
In a related note, Black Gate N 50V/4.7uF caps appear to be back in stock at the Osaka stores.
-R
And the last phonoclone is now sold, so that's it until Batch 4, scheduled for early 2006.
After listening to brainspex's comments I'm looking into what I can do about the regulation circuitry, but I dont think I have room on the PCBs to fit the LM317s and associated components.
Increasing the board size would immediately double the cost.
Probably the most efficient alternative would be to design a separate PCB with either four or eight regulators. This would make using LM317s a fairly simple affair...
/R
After listening to brainspex's comments I'm looking into what I can do about the regulation circuitry, but I dont think I have room on the PCBs to fit the LM317s and associated components.
Increasing the board size would immediately double the cost.
Probably the most efficient alternative would be to design a separate PCB with either four or eight regulators. This would make using LM317s a fairly simple affair...
/R
See the attached image for an explanation of how to use the phonclone PCB with external regulators. Basically, leave out the 78xx/79xx and C8,9,10,11. Bridge over the input and output connections of the regulator holes with wire. This is also the configuration for using the phonoclone with batteries.
Anyway, back to regulators. Having done some reading around this forum, and looking at the costs involved, it sems to me that either you go the full-monty and build the Jung super regulator (or rather eight of them), or you settle for cheap-but-better-than-fixed-regulator types LM3x7.
I dont see any attractive alternatives in the middle ground.
I was thinking originally of building a compound regulator circuit with a quad op-amp, four pass transistors, two voltage references for two positive and two negative outputs to power 1 phonoclone or 2 VSPS channels, but it seemed like a lot of work re-inventing the wheel for little tangible benefit.
I'm certainly open to suggestions.
/R
Anyway, back to regulators. Having done some reading around this forum, and looking at the costs involved, it sems to me that either you go the full-monty and build the Jung super regulator (or rather eight of them), or you settle for cheap-but-better-than-fixed-regulator types LM3x7.
I dont see any attractive alternatives in the middle ground.
I was thinking originally of building a compound regulator circuit with a quad op-amp, four pass transistors, two voltage references for two positive and two negative outputs to power 1 phonoclone or 2 VSPS channels, but it seemed like a lot of work re-inventing the wheel for little tangible benefit.
I'm certainly open to suggestions.
/R
