Subjective and Objective Together
Edited by dice45: thread was split here; original thread: "Remove plastic covers from capacitors" in the Electronics & Parts board
If it sounds decent and makes my feet tap, hell I don't care about measurements, only nowadays it has to be good to do that.
Steve, you make audio isolation transformer boxes yeah ?.
Can you give some objective and subjective findings and corellations of the benefits of these ?.
This is a polite question so no spam callers thanks.
Eric.
Edited by dice45: thread was split here; original thread: "Remove plastic covers from capacitors" in the Electronics & Parts board
If it sounds decent and makes my feet tap, hell I don't care about measurements, only nowadays it has to be good to do that.
Steve, you make audio isolation transformer boxes yeah ?.
Can you give some objective and subjective findings and corellations of the benefits of these ?.
This is a polite question so no spam callers thanks.
Eric.
Re: Subjective and Objective Together
And that's EXACTLY how I look at it.
Well objectively it's pretty simple. By breaking the DC ground connection between components, you eliminate ground loop and interchassis currents that subsequently produce noise. They also have a natural low pass filter function that filters out RF which can also come from CDPs/DACs which cable shielding has no effect on.
Subjectively I really can't offer much. As I've said previously, I'm wholly right brained when it comes to listening. I don't take the fly speck, analytical approach that many others do and break things down into tiny little pieces and analyze them separately and then try and reach some conclusion.
I just take it in as a whole and decide intuitively whether I like it or not.
Of course if there's some rather gross anomaly that sticks out like a sore thumb, that can catch my attention. But beyond that I'm afraid I'm at a disadvantage when it comes to relating precisely WHY I might prefer something.
Not to worry. I'm not a "salesman" in the perjorative sense of the word.
Besides, this being a DIY forum, I'd just as soon suggest that if you had an interest, you just buy the raw transformers from Jensen or Sowter and install them INSIDE the component itself which would be preferable to an external, inline solution.
se
mrfeedback said:
And that's EXACTLY how I look at it.
Well objectively it's pretty simple. By breaking the DC ground connection between components, you eliminate ground loop and interchassis currents that subsequently produce noise. They also have a natural low pass filter function that filters out RF which can also come from CDPs/DACs which cable shielding has no effect on.
Subjectively I really can't offer much. As I've said previously, I'm wholly right brained when it comes to listening. I don't take the fly speck, analytical approach that many others do and break things down into tiny little pieces and analyze them separately and then try and reach some conclusion.
I just take it in as a whole and decide intuitively whether I like it or not.
Of course if there's some rather gross anomaly that sticks out like a sore thumb, that can catch my attention. But beyond that I'm afraid I'm at a disadvantage when it comes to relating precisely WHY I might prefer something.
Not to worry. I'm not a "salesman" in the perjorative sense of the word.
Besides, this being a DIY forum, I'd just as soon suggest that if you had an interest, you just buy the raw transformers from Jensen or Sowter and install them INSIDE the component itself which would be preferable to an external, inline solution.
se
Steve,
Thanks for the clarification.
Me,I just can't help getting the feeling that in audio the same thing happens as in the pc world.
Things getting ported from the pro (mainframe) world into the consumer market (PC).
By no means a bad thing as such of course.
BTW,wouldn't it be a good idea then to market such a product as yours with XLR in and outputs,or a combination of those ?
Rgds,
Thanks for the clarification.
Me,I just can't help getting the feeling that in audio the same thing happens as in the pc world.
Things getting ported from the pro (mainframe) world into the consumer market (PC).
By no means a bad thing as such of course.
BTW,wouldn't it be a good idea then to market such a product as yours with XLR in and outputs,or a combination of those ?
Rgds,
Steve,
what you say above i can follow and i am with you as far as Jensen trannies are concerned.
I have a pair of Jensen JT-346 as MC input trannie. Except the right piece of wire, this trannie is the best MC input device i came across so far. It is expensive but does make up for it partially by not needing a power supply (and by providing potential isolation for the case i want to have my input grids at -100V....
). TME an active MC headamp needs dramatic effort for the power supply, preferable NiCd batteries and all the hassle keeping them properly loaded.
what you say above i can follow and i am with you as far as Jensen trannies are concerned.
I have a pair of Jensen JT-346 as MC input trannie. Except the right piece of wire, this trannie is the best MC input device i came across so far. It is expensive but does make up for it partially by not needing a power supply (and by providing potential isolation for the case i want to have my input grids at -100V....
). TME an active MC headamp needs dramatic effort for the power supply, preferable NiCd batteries and all the hassle keeping them properly loaded.
fdegrove said:Steve,
Thanks for the clarification.
Me,I just can't help getting the feeling that in audio the same thing happens as in the pc world.
Things getting ported from the pro (mainframe) world into the consumer market (PC).
By no means a bad thing as such of course.
Certainly.
I came into transformers originally as a musician. I got tired of being zapped by touching other equipment or microphones while also touching the strings on my guitar so I fitted my guitar with a transformer and voila. Zap free.
Sure. And if all goes well, I'll be doing just that. Just that my primary goal was to address users with unbalanced inputs as they are the most inherently problematic in that regard.
You can actually feed the InterFace from a balanced source (seeing as the input is inherently balanced). Just need to use an XLR/RCA cable.
Thanks for the comments.
se
dice45 said:
Whew! Great! Finally got on the same page! Let's see if we can keep the positive vibe going.
I have a pair of Jensen JT-346 as MC input trannie. Except the right piece of wire, this trannie is the best MC input device i came across so far. It is expensive but does make up for it partially by not needing a power supply (and by providing potential isolation for the case i want to have my input grids at -100V....
Yeah. In my own experience I really haven't found anything that can quite touch a top notch transformer in certain applications. And they've such an elegant simplicity (basically just two lengths of wire and a chunk of nickel) that works well with some of my underlying philosophies.
A project I have on the drawing board now is a low power (about 5-6 watts) single-ended integrated amplifier that will use transformers for attenuation as well as all of the circuit's voltage gain. The battery powered active devices being used as just simple emitter followers for impedance buffering.
Here's a simplified schematic illustrating the basic concept:
<center>
<img src="http://www.q-audio.com/images/tao.jpg">
</center>
Once I get 'round to settling on some higher efficiency speakers, I'll start on the final development. And if I don't **** off too many people here in the meantime, I'll post it here as a project once it's completed.
se
BATTERIES
Guys,
Sorry to sidetrack here,what exactly is the problem with the batteries here?
preferable NiCd batteries and all the hassle keeping them properly loaded.
I was thinking of experimenting a little by building an all battery supply for headamp through preamp.(tubes B+ 24VDC)
The heaters would be supplied by a regular transformer fed by AC form the mains.
I thought if I bought a couple of 12V NiCads and the PSU (battery)
from Teres I would be off to a good start ?
The Teres come with a load detection system so they're not on charge when in use.
If any of you would have objections I would be glad to hear about it.
Rgds,
Guys,
Sorry to sidetrack here,what exactly is the problem with the batteries here?
preferable NiCd batteries and all the hassle keeping them properly loaded.
I was thinking of experimenting a little by building an all battery supply for headamp through preamp.(tubes B+ 24VDC)
The heaters would be supplied by a regular transformer fed by AC form the mains.
I thought if I bought a couple of 12V NiCads and the PSU (battery)
from Teres I would be off to a good start ?
The Teres come with a load detection system so they're not on charge when in use.
If any of you would have objections I would be glad to hear about it.
Rgds,
Re: BATTERIES
I think he's referring to the additional care and feeding with regard to recharging the batteries. And of course this is within the context of a moving coil step-up where there's no inherent need for an active circuit in the first place. In other words, he's comparing the difference between a simple passive solution versus an active one.
24 volt B+? Can you get away with that with tubes?
Well I guess if you can get by with a 24 volt B+...
Might want to give the NiMHs a try too. They don't have the memory effects of NiCds.
Don't see anything to object to except perhaps that 24 volt B+ but tubes aren't my specialty so I'm just going by intuition here.
se
fdegrove said:
I think he's referring to the additional care and feeding with regard to recharging the batteries. And of course this is within the context of a moving coil step-up where there's no inherent need for an active circuit in the first place. In other words, he's comparing the difference between a simple passive solution versus an active one.
24 volt B+? Can you get away with that with tubes?
Well I guess if you can get by with a 24 volt B+...
Might want to give the NiMHs a try too. They don't have the memory effects of NiCds.
Don't see anything to object to except perhaps that 24 volt B+ but tubes aren't my specialty so I'm just going by intuition here.
se
BATTERIES
Steve,
Thanks for your reply.
If anyone is interested in the preamp minus MC part which I have have described to Marjan in the tubes section:
see:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=5327
see:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=5963
Yes the NiMH's are the ones to go for,no need for deep discharge and all that rubbish.
I admit to being a bit biased against MC transformers but I may as well give the Jensens a try.
Thks,
Steve,
Thanks for your reply.
If anyone is interested in the preamp minus MC part which I have have described to Marjan in the tubes section:
see:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=5327
see:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=5963
Yes the NiMH's are the ones to go for,no need for deep discharge and all that rubbish.
I admit to being a bit biased against MC transformers but I may as well give the Jensens a try.
Thks,
Back then when NiMH was unavailable, NiCd had the lowest Z. amde listening comparisons, using my SE FET MC headamp i posted about earlier here. NiCd won hands-down over lead-jelly or lead-fluid batteries; AC-fed PS was worst by far.
Last month i got informed by a model airplane geek that NiCd still is top choice for ultra low Z. Just a pain to maintenance NiCd.
My point was: once you tried batteries, you won't be willing to step back to AC, but the trannie sounds better and does not need any PS and batteries at all.
Frank,
no objection against the Teres thing, provided the charge-monitoring and re-loading circuit meets its expectations and keeps its promises. About which i have no info.
Steve,
the Jensens convinced me that much that i abandoned my dreams of an MC-sensitive all-tube phono preamp. My wishful thinking on tubes being noise-free enough for an Ortofon MC. 0.2mV for 0dB.
And before i always considered the mentioned SE FET headamp as best solution but still deterioating sonics, somehow taking the ease away, although under critical AB-ing no flaw could be spotted. Not so with the Jensens. I am not regretting here i put in another amplifying device, okok wire is still better, but then macrodynamics are spoiled and lame and µdynamics are inexistent on low levels, they drown in the noise carpet then.
Heuh?
Dice,
I'm afraid I'm a bit at a loss here:
I'm just guessing,do you mean comparing the sound of the Jensen MC stepups to a piece of (ok ,good quality) wire?
Also,while we're at it:
I notice the Jensen you have come in two versions at the same price only differing in turns ratio?
"The JT-346-AX is designed to be incorporated into custom moving coil preamp designs. It provides a perfect impedance match for premium low noise amplifiers like the AD797. It works best with cartridges that meet the criteria for either the JT-34K-DX or JT-44K-DX. The JT-346-AX may be wired with the 3 primary windings in series or in parallel to accomodate both general impedance ranges of moving coil cartridges. It does not have the higher step-up ratios of the the other Jensen transformers though, so is not normally suitable for use directly with a conventional RIAA preamp, except in the case of very high output cartridges."
JT-346-AX $ 25:600 1:4 +4dBu 0.015% <0.001% -0.05dB/
-0.03dB 220kHz
JT-346-AX $ 3:630 1:12 -5dBu 0.015% <0.001% -0.05dB/
-0.03dB 220kHz
Am I correct in assuming this one isn't particalurly suited to the lower output MC's?
Any idea how the other two models sound?
I need drop down transparency from my MC all the way through,any veiling and the thingies go to the sin bin (indefinitely).
Thks,
Dice,
I'm afraid I'm a bit at a loss here:
I'm just guessing,do you mean comparing the sound of the Jensen MC stepups to a piece of (ok ,good quality) wire?
Also,while we're at it:
I notice the Jensen you have come in two versions at the same price only differing in turns ratio?
"The JT-346-AX is designed to be incorporated into custom moving coil preamp designs. It provides a perfect impedance match for premium low noise amplifiers like the AD797. It works best with cartridges that meet the criteria for either the JT-34K-DX or JT-44K-DX. The JT-346-AX may be wired with the 3 primary windings in series or in parallel to accomodate both general impedance ranges of moving coil cartridges. It does not have the higher step-up ratios of the the other Jensen transformers though, so is not normally suitable for use directly with a conventional RIAA preamp, except in the case of very high output cartridges."
JT-346-AX $ 25:600 1:4 +4dBu 0.015% <0.001% -0.05dB/
-0.03dB 220kHz
JT-346-AX $ 3:630 1:12 -5dBu 0.015% <0.001% -0.05dB/
-0.03dB 220kHz
Am I correct in assuming this one isn't particalurly suited to the lower output MC's?
Any idea how the other two models sound?
I need drop down transparency from my MC all the way through,any veiling and the thingies go to the sin bin (indefinitely).
Thks,
Re: Heuh?
Yes. Notice that they say it can be used with cartridges which meet the criteria for either the 34K-DX or 44K-DX. Look up higher and it'll show you the criteria for each of those. What they mean is that depending how you wire the primaries, you can use it for either set of criteria.
Not on its own. It's intended to be used in an MC preamp where additional gain is provided by active circuitry.
The others, with their 1:37 step up, provide all of the voltage gain and are intended to be plugged straight into the input of a MM phono stage.
Dice will have to help you there. I'm still digital.
se
fdegrove said:Dice,
I notice the Jensen you have come in two versions at the same price only differing in turns ratio?
Yes. Notice that they say it can be used with cartridges which meet the criteria for either the 34K-DX or 44K-DX. Look up higher and it'll show you the criteria for each of those. What they mean is that depending how you wire the primaries, you can use it for either set of criteria.
Not on its own. It's intended to be used in an MC preamp where additional gain is provided by active circuitry.
The others, with their 1:37 step up, provide all of the voltage gain and are intended to be plugged straight into the input of a MM phono stage.
Any idea how the other two models sound?
I need drop down transparency from my MC all the way through,any veiling and the thingies go to the sin bin (indefinitely).
Dice will have to help you there. I'm still digital.
se
I've tried a number of MC stepup transformers (Lundahl, Jensen, Tango, Kanno etc.) Indeed, the better ones sounded quite good. But to me they didn't sound as revealing as the best discrete headamp circuits that we were able to come up with.
I felt that there was a noticeable filtering out of information with the transformers which the headamp didn't have. OTOH, you could also say the transformers cleaned up the sound and organized it.
Depending on what phono equalizer followed, sometimes the results were better with the transformer, and sometimes the results were better with the headamp.
However, I felt that the best sound was obtained by combining the best headamp circuit that I was able to devise with the best phono equalizer circuit that I was able to make.
Caveat: While the best headamp circuit sounded better to me than the transformers, I have heard many headamp circuits that didn't sound nearly as good as a decent transformer. As always, implementation is a major issue.
YMMV, jonathan carr
I felt that there was a noticeable filtering out of information with the transformers which the headamp didn't have. OTOH, you could also say the transformers cleaned up the sound and organized it.
Depending on what phono equalizer followed, sometimes the results were better with the transformer, and sometimes the results were better with the headamp.
However, I felt that the best sound was obtained by combining the best headamp circuit that I was able to devise with the best phono equalizer circuit that I was able to make.
Caveat: While the best headamp circuit sounded better to me than the transformers, I have heard many headamp circuits that didn't sound nearly as good as a decent transformer. As always, implementation is a major issue.
YMMV, jonathan carr
Transformers Are Good
Steve,
On my workbench reference system I have a 1:1 transfomer isolation box between my preamp and power amp.
I also incorporated DPDT switches wired as reversing switches on the primaries to give selectable audio polarity.
Even though I am using as cheap as I can find car audio Taiwan made signal trannies, the system sound is very good indeed, and the polarity switching is a must in my opinion/experience.
Polarity switching is a mandatory feature I reckon, and applicable to your product.
Eric.
Steve,
On my workbench reference system I have a 1:1 transfomer isolation box between my preamp and power amp.
I also incorporated DPDT switches wired as reversing switches on the primaries to give selectable audio polarity.
Even though I am using as cheap as I can find car audio Taiwan made signal trannies, the system sound is very good indeed, and the polarity switching is a must in my opinion/experience.
Polarity switching is a mandatory feature I reckon, and applicable to your product.
Eric.
MC TRANSFORMER
Jonathan,Steve et all,
I appreciate your input.
Reading you Jonathan,and especially knowing and greatly respecting the cartridges you helped to design, I think I read you well.
This convinces me more to pursue my quest to design the mere impossible:designing an integrated tube headamp fed by a battery PSU.
IMHO this combination has the potential of avoiding compromises so often found in most commercial designs.
Whatever hurdles I come across will be posted here ( the basics have been in service for five years and have baffled many a dyed in the wool audiophile) and after resolving all, the circuit diagram will be made available to the community.
And I have this gut feeling that Bernhard and others are just waiting for a "tranny" beater??
Yrs sincerely,
Jonathan,Steve et all,
I appreciate your input.
Reading you Jonathan,and especially knowing and greatly respecting the cartridges you helped to design, I think I read you well.
This convinces me more to pursue my quest to design the mere impossible:designing an integrated tube headamp fed by a battery PSU.
IMHO this combination has the potential of avoiding compromises so often found in most commercial designs.
Whatever hurdles I come across will be posted here ( the basics have been in service for five years and have baffled many a dyed in the wool audiophile) and after resolving all, the circuit diagram will be made available to the community.
And I have this gut feeling that Bernhard and others are just waiting for a "tranny" beater??
Yrs sincerely,
ABSOLUTE PHASE
Hello,
You may find absolute phase may differ from one recording to the other.
According to the actual phase respect of your current system it may or may not be respecting absolute phase irrespective of its source.
This reminds me of the Counterpoint SA PI,which did the same actively (tube circuit).
Some people are more sensitive to it than others I've been told but it sure does make a lot of difference to most.
And yes that's a very good idea to incorporate in an isolation transformer.Geeh...are we really that slow to see the obvious?
Excellent idea!Five star and the economy award to you.
Introducing a DPDT switch, a piece of wire and some soldering can't up the price too much?
Steve?
Brilliant!
Whish I thought of that.
Cheers,
Hello,
You may find absolute phase may differ from one recording to the other.
According to the actual phase respect of your current system it may or may not be respecting absolute phase irrespective of its source.
This reminds me of the Counterpoint SA PI,which did the same actively (tube circuit).
Some people are more sensitive to it than others I've been told but it sure does make a lot of difference to most.
And yes that's a very good idea to incorporate in an isolation transformer.Geeh...are we really that slow to see the obvious?
Excellent idea!Five star and the economy award to you.
Introducing a DPDT switch, a piece of wire and some soldering can't up the price too much?
Steve?
Brilliant!
Whish I thought of that.Cheers,
Frank, thanks for the compliments and the award. 
The transformers that I used are intended for car audio line level DC isolation, and come mounted in a small box with RCA leads attached and cost AUS$12.00 wholesale.
These are cheap Taiwan transformers but they do a fine enough job.
I have not tried Jensens so I cannot comment on sonics differences.
IMO a hi-fi is not worth having without polarity switching, so this was/is my budget soloution.
The only precaution is that the secondaries need to be loaded down to avoid HF peaking response.
Eric.
PS - If you hang around you'll get to hear a few more gems like this on the forum from time to time.
The transformers that I used are intended for car audio line level DC isolation, and come mounted in a small box with RCA leads attached and cost AUS$12.00 wholesale.
These are cheap Taiwan transformers but they do a fine enough job.
I have not tried Jensens so I cannot comment on sonics differences.
IMO a hi-fi is not worth having without polarity switching, so this was/is my budget soloution.
The only precaution is that the secondaries need to be loaded down to avoid HF peaking response.
Eric.
PS - If you hang around you'll get to hear a few more gems like this on the forum from time to time.
Re: ABSOLUTE PHASE
This reply goes out to mrfeedback as well.
No, it wouldn't up the price too much. Which is why I included a DPDT switch to change polarity (you can see them in the internal photograph in the EtM review, they're the blocky looking things on the far sides of the board next to the transformers).
However the switches aren't accessible from the outside. I intended them to be used as a set-it-and-forget-it so users could use it for reversing the polarity of the component that's feeding the InterFace in the event that the component inverted polarity.
Because the InterFace should be mounted as close as possible to the inputs of the component it's feeding, it wouldn't always be practical to get at it on a consistent basis as one would need to do if they're changing polarity from recording to recording.
Besides, any preamp worth its salt should have a polarity switch already.
Nevertheless, thanks for the comments!
se
fdegrove said:Introducing a DPDT switch, a piece of wire and some soldering can't up the price too much?
Steve?
Brilliant!
This reply goes out to mrfeedback as well.
No, it wouldn't up the price too much. Which is why I included a DPDT switch to change polarity (you can see them in the internal photograph in the EtM review, they're the blocky looking things on the far sides of the board next to the transformers).
However the switches aren't accessible from the outside. I intended them to be used as a set-it-and-forget-it so users could use it for reversing the polarity of the component that's feeding the InterFace in the event that the component inverted polarity.
Because the InterFace should be mounted as close as possible to the inputs of the component it's feeding, it wouldn't always be practical to get at it on a consistent basis as one would need to do if they're changing polarity from recording to recording.
Besides, any preamp worth its salt should have a polarity switch already.
Nevertheless, thanks for the comments!
se
Re: MC TRANSFORMER
What you might consider is getting the best of both worlds.
As I mentioned previously, the Jensen 346-AX is intended to be used in a circuit which uses active circuits to provide additional voltage gain. To that end, the 346-AX doesn't offer nearly as much voltage gain as the other two.
The more a transformer has to step up the voltage, the more compromises have to be made and the more its ultimate performance is sacrificed. Of course this applies to active circuits as well.
This may explain some of the dissatisfaction by some of wholly passive solutions where the entire burden is on a singular device.
With a hybrid, you get a little gain passively from the transformer and you get a little gain actively from the tube stage. Then neither has to work quite as hard if each were used on their own. Not to mention that the trannie will give you common-mode noise rejection far exceeding anything any active circuit can give you.
One of my personal design philosophies has been to avoid extremes and work to achieve a pleasing balance between compliments. It's been quite successful so far me. At least according to what my Zen Hedonist side tells me.
Great! I hope whatever route you take leads to success!
Aren't there laws against trannie beating? If not, there outta be!
se
fdegrove said:
What you might consider is getting the best of both worlds.
As I mentioned previously, the Jensen 346-AX is intended to be used in a circuit which uses active circuits to provide additional voltage gain. To that end, the 346-AX doesn't offer nearly as much voltage gain as the other two.
The more a transformer has to step up the voltage, the more compromises have to be made and the more its ultimate performance is sacrificed. Of course this applies to active circuits as well.
This may explain some of the dissatisfaction by some of wholly passive solutions where the entire burden is on a singular device.
With a hybrid, you get a little gain passively from the transformer and you get a little gain actively from the tube stage. Then neither has to work quite as hard if each were used on their own. Not to mention that the trannie will give you common-mode noise rejection far exceeding anything any active circuit can give you.
One of my personal design philosophies has been to avoid extremes and work to achieve a pleasing balance between compliments. It's been quite successful so far me. At least according to what my Zen Hedonist side tells me.
Great! I hope whatever route you take leads to success!
Aren't there laws against trannie beating? If not, there outta be!
se
TO TRANNIE OR NOT TO TRANNIE ?
Folks,
Thanks for the input.
Guess it's all a matter of doing the ultimate balancing (no pun intended) act,right?
However regarding the ISO trannies:
Absolute phase of the entire system is one thing to get right surely.
But I think Eric means he must have a way to check and control absloute phase of his media (CD,vinyl etc.).
It's a shame but all too many recordings are made with absolute phase reversed.
And no,I don't even want to think about all those multi miked acrobacies where they didn't even bother to check each feed's input phase...
Up to you Steve to put that switch on the box where it can be reached.
Rgds,
Folks,
Thanks for the input.
Guess it's all a matter of doing the ultimate balancing (no pun intended) act,right?
However regarding the ISO trannies:
Absolute phase of the entire system is one thing to get right surely.
But I think Eric means he must have a way to check and control absloute phase of his media (CD,vinyl etc.).
It's a shame but all too many recordings are made with absolute phase reversed.
And no,I don't even want to think about all those multi miked acrobacies where they didn't even bother to check each feed's input phase...
Up to you Steve to put that switch on the box where it can be reached.
Rgds,
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