Teddy Pardo PSU for Arcam rDAC

[eggontoast]

OK. I'll try to keep it brief and simple as much as possible.

every DAC has to have an analog output stage to amplify weak analog sygnal post D/A conversion into something a line level..........

It's a good job that the audio signal hasn't been passed through any op-amps during the recording process......wait, no, oh yes I forgot it has probably about 100 of them. I don't think one more is going to make a difference do you.

 

[acalex]

What's the difference? Thanks!

OK. I'll try to keep it brief and simple as much as possible.

every DAC has to have an analog output stage to amplify weak analog sygnal post D/A conversion into something a line level preamp can wok with (usually 2V RMS). plethora of DACs (and all budget ones) use off-the-shelf industrial opams to do the job. opamps are solid state (transistor) based devices. transistors amplify different frequencies in not to much linear way, i.e. some frequencies are amplified more than others. this is not acceptable in audio where linear freq response is always sought. so one day someone came up with an idea how to solve this problem using negative feedback. negative feedback attenuates frequencies that are amplified too much. it should be noted here that the worse quality transformers used the less linear amplifying characteristics are.

how it works. original sygnal passes through amplifying stage where it's amplified. then it's most likely too much amplified so it needs to be attenuated therefore a part of the amplified signal, but out of phase to the original sygnal, is fed back into the amplifying stage to do the job. this solution is a brilliant idea if we deal with stable sygnals. however, musical sygnal is faaaar from being stable. therefore when the fed back sygnal gets into amplifying stage it tries to regulate something that it should not because new sygnal is now completely different from what it originaly was. all this of course happens very quickly but still, due to the nature of musical sygnal, feedback system is always lagging behind. in one word it distorts the output sygnal in that it makes it ever so slightly different from the original.

that doesn't happen when no feedback is used. what you get in return is better low level musical clues retrieval hence better ambience retrialval, better low level dynamics, truer timbre of instruments and voices and sounds, much bigger depth of sounstage (it has a lot to do with ambience retrieval), more stable and precise positioning of images in soundstage.

if you've got a feedbackless DAC (or other devices) you can be sure of one thing, that high quality, having more linear characteristics components were used in output stage because you can't go without feedback with basic components.

there's another big advantage of ditching feedback. if you use feedback you get a bonus in greatly reduced THD figures. every active electrical component (i.e. transistor) generates harmonics next to what originally was asked to amplify. usually it's second order harmonics and is quite large % of original sygnal. feedback reduces greatly this 2nd order harmonics but it introduces many other, low level harmonics (3rd, 4th, 5th, 6th, 7th...) in return. this is the main reason solid state devices sound "shrill" and "bright" compared to tube gear, where you usually get a lot of 2nd order harmonics and nothing else. human ears don't like high order harmonics, even low level.

Wow, a lot of stuff...need to re-read this carefully! I might dig more into this...I am not in a rush to change/upgrade my DAC so I would like to take all the options into consideration. Do you have any name to suggest? To be honest I am not aware of any DAC which is feedbackless....

Thanks

 

[oldric_naubhoff]

It's a good job that the audio signal hasn't been passed through any op-amps during the recording process......wait, no, oh yes I forgot it has probably about 100 of them. I don't think one more is going to make a difference do you.

a good point but not necessarily valid. I'm not a recording engineer or recording equipment designer, but my knowledge and logic tells me that there's actually no op-amps involved in recording process. (I may just as well be totally wrong so would welcome any correction, if such is needed, from a knowledgeable person).

when a natural sound is captured in studio by a mic the signal travels straight into ADC section of recorder (I assume that majority of today's recording studios work with digital material, not analogue). then any subsequent mastering/ processing takes place in digital domain - no op-amps needed there. producers need of course to check their work how it sounds. and here I'll admit that majority of reproducing/ monitoring equipment uses negative feedback in its design. however, since monitoring has nothing to do with recording therefore original signal can't be altered by feedback loops at any stage of sound processing.

the situation gets even more interesting with regards to electronic music which itself, by large extent, is conceived in digital domain - no "physical" recording is even needed.

back in the days of analogue recording techniques; I can't bet my life on this assumption but I wouldn't be surprised if passive attenuators, rather than active filters, were used in mastering process. just a guess...

another think is the quality of recording gear. I don't know what they use in Abbey Road but I would be surprised to find out that some Behringer or M-Audio or any other budget brand found its home there, or any other (self)respected recording studio for that matter.

 

[Overdose]

It's a good job that the audio signal hasn't been passed through any op-amps during the recording process......wait, no, oh yes I forgot it has probably about 100 of them. I don't think one more is going to make a difference do you.

a good point but not necessarily valid. I'm not a recording engineer or recording equipment designer, but my knowledge and logic tells me that there's actually no op-amps involved in recording process.

It's not just about recording though. It's about mixing as well, which involves all kinds of manipulation of sounds and levels and is not done exclusively in either the digital or analogue domain.

The chances are, that the recording process has indeed used many op-amps, particularly if a mixing desk has been used. I do see your point about recording directly to digital, but it is over simplified and not neccessarily valid.

I also, may just as well be totally wrong so would welcome any correction, if such is needed, from a more knowledgeable person.

 

[oldric_naubhoff]

Do you have any name to suggest? To be honest I am not aware of any DAC which is feedbackless....

Thanks

the best buy award from me would go to Linnenberg UDC1. drawback is that it's only a USB DAC, however with built in M2Tech asynchronous USB receiver. it stands now at E890 until the end of the year. you can try it out and return if not satisfied.

other companies making feedbackless gear that I'm aware of are: Ayre, Ayon, Pathos, Bergman. I guess this list doesn't exhaust the subject but since such products are niche it's hard to source manufacturers. none of these brands are budget level. I guess you pay for the technology, high quality parts and low numbers production runs. but what you get is a truly hi-fi or even high-end product that's bound to sound great.

if at some point you decide that you want to make listening to music a serious interest you'll start thinking about upgrading. maybe then you'll remember my advice. in the mean time I'd suggest you should read as much as possible about technology around music reproduction, of course if you find such lecture interesting. knowledge helps in making concious decisions.

 

[oldric_naubhoff]

The chances are, that the recording process has indeed used many op-amps, particularly if a mixing desk has been used. I do see your point about recording directly to digital, but it is over simplified and not neccessarily valid.

well, for instance Radiohead's "OK Computer" was entirely produced using Cubasse VST and it was min 90-ties. I don't think the trend was reversed. and mixing desks are often used not as active fitering devices but as interface for the soft.

 

[jerry klinger]

Wow what a load of awful advice. You are pretty much worse off from before you asked the question.

Either DAC is good and I would choose the one you prefer the sound of.

If I wanted a Rega DAC I'd own one. I don't. I preferred my rDac with PSU.

If I wanted an £800 DAC I'd own one. I don't. I prefer my upgraded rDac with PSU.

I've rarely agreed more with a forum post. The usual list of suspects leaps up to offer advice based almost certainly on half-digested magazine reviews and price lists.

Like Danny, I've tried both the Rega DAC and the Arcam rdac at home, and preferred the rdac - and that was with the (wonderful) Rega Brio-R. The Rega DAC in some ways is more informative and in some ways not. I preferred the presentation (lighter, less bassy and dark). But then my ears are not the OP's. The rdac does a great job and has both asynchronous USB (which helps) and 24/96 on USB - which the Rega doesn't. Important this I feel.

You can buy a power supply from Maplin's for £35 which will improve the sound of the rdac. Russ Andrews take this (type of) PSU and add a capacitor and some Kimber cable (according to their website) and ask £95 for it. I've gone for the Maplin's.

As for Teddy Pardo - an Israeli company selling off ebay. Well, it's your money.... I wouldn't.

 

[acalex]

Do you have any name to suggest? To be honest I am not aware of any DAC which is feedbackless....

Thanks

the best buy award from me would go to Linnenberg UDC1. drawback is that it's only a USB DAC, however with built in M2Tech asynchronous USB receiver. it stands now at E890 until the end of the year. you can try it out and return if not satisfied.

other companies making feedbackless gear that I'm aware of are: Ayre, Ayon, Pathos, Bergman. I guess this list doesn't exhaust the subject but since such products are niche it's hard to source manufacturers. none of these brands are budget level. I guess you pay for the technology, high quality parts and low numbers production runs. but what you get is a truly hi-fi or even high-end product that's bound to sound great.

if at some point you decide that you want to make listening to music a serious interest you'll start thinking about upgrading. maybe then you'll remember my advice. in the mean time I'd suggest you should read as much as possible about technology around music reproduction, of course if you find such lecture interesting. knowledge helps in making concious decisions.

Whic one you have?

 

[oldric_naubhoff]

Whic one you have?

I stuck with Pathos. it sounds great and also has great styling. I've got Digit CDP and InTheGroove mkII phono preamp. I also have Classic One mkIII integrated amp but I'll definitely upgrade to Inpol2 (this one is special design class A feedbackless integrated amp) when a suitable chance arises. I don't want to pay full price on it. Pathos don't have a stand alone DAC yet but I know they work on it. don't know when it will hit the shops but I know it's not going to be cheap; about E 3000...

I was considering to upgrade my laptop soundcard and then I came across this Linnenberg UDC1. but in the end I decided not to buy it since I only listen to music from CD and LP. I use computer only for watching films now so I thought I would be a waste of mony if I spent some E 900 for a soundcard upgrade.

P.S. I've noticed I made a mistake in my one of my previous posts. It should have been Densen not Bergmann.

 

[acalex]

I think soon I will order the UDC1 and try it at home. It comes from Germany so it's not that expensive to ship to Belgium and they have a 30days return policy which I can use....they conferm the listening experience is something completely different from commercial DACs...I am now curios to try this. They use a M2Tech interface (capable of 32bit 384KHz), only USB (which is the only connection I need), linear regulator technology for PSU...let's see!

The only problem might be the connection DAC amply since the only connectio this DAC has is XLR right and left. I guess I need two XLR --> RCA cables (one for left and one for right), correct?

The seller said that a customer sold the Accuphase DC-801 and Weiss firewire to SPDIF INT202 converter because he bought this DAC...well ok it's marketing stuff but they anyway offer a 30 days return policy...which is quite safe I would say! I have plenty of time to try the DAC at home and get a precise idea on the product...

Riding the wild side... :cheers:

 

[oldric_naubhoff]

I think soon I will order the UDC1 and try it at home. It comes from Germany so it's not that expensive to ship to Belgium and they have a 30days return policy which I can use....they conferm the listening experience is something completely different from commercial DACs...I am now curios to try this. They use a M2Tech interface (capable of 32bit 384KHz), only USB (which is the only connection I need), linear regulator technology for PSU...let's see!

don't forget to share your impressions

I'm quite sure you'll be satisfied. furthermore, it will be a worthy match for a more expensive amp + speakers combo than what you have right now, should you wish to upgrade in the future. (now disrespect intended ). so it's definitely a future proof buy.

The only problem might be the connection DAC amply since the only connectio this DAC has is XLR right and left. I guess I need two XLR --> RCA cables (one for left and one for right), correct?

well, this DAC is fully balanced and not just equipped with XLR connectors, like many chinese products. (true balanced topology has great advantages over single ended (cheaper one) in rejecting common mode noise, so in conjunction with proper power supply this DAC will be dead silent). it's better if you use XLR interconnects but if you can't accommodate XLRs that's not a problem. in manual the manufacturer advices to use XLR to RCA adaptors from Neutrik (Neutrik NA2FPMF). they are quite inexpensive. on ebay you can have them for less than E 10/ piece.

 

[acalex]

I think soon I will order the UDC1 and try it at home. It comes from Germany so it's not that expensive to ship to Belgium and they have a 30days return policy which I can use....they conferm the listening experience is something completely different from commercial DACs...I am now curios to try this. They use a M2Tech interface (capable of 32bit 384KHz), only USB (which is the only connection I need), linear regulator technology for PSU...let's see!

don't forget to share your impressions

I'm quite sure you'll be satisfied. furthermore, it will be a worthy match for a more expensive amp + speakers combo than what you have right now, should you wish to upgrade in the future. (now disrespect intended ). so it's definitely a future proof buy.

The only problem might be the connection DAC amply since the only connectio this DAC has is XLR right and left. I guess I need two XLR --> RCA cables (one for left and one for right), correct?

well, this DAC is fully balanced and not just equipped with XLR connectors, like many chinese products. (true balanced topology has great advantages over single ended (cheaper one) in rejecting common mode noise, so in conjunction with proper power supply this DAC will be dead silent). it's better if you use XLR interconnects but if you can't accommodate XLRs that's not a problem. in manual the manufacturer advices to use XLR to RCA adaptors from Neutrik (Neutrik NA2FPMF). they are quite inexpensive. on ebay you can have them for less than E 10/ piece.

I know, it's my first set and I wanted to start more on a low profile...
But my intention is to update in the future, that's for sure!!!

 

[CnoEvil]

Pathos don't have a stand alone DAC yet but I know they work on it. don't know when it will hit the shops but I know it's not going to be cheap; about E 3000...

[/quote]

This is very interesting.....do you know any further details and how did you come by the information?

Cheers

Cno

 

[acalex]

How different would be the listening experience? I mean...what difference I might expect compared to a commercial DAC?

 

[oldric_naubhoff]

This is very interesting.....do you know any further details and how did you come by the information? Cheers Cno

well, I just e-mailed Pathos and asked . they are very approachable company. I'm not quite sure if I can pass on the info but since they gave me that info it must not be too secret. so, here's what I know:
"With reference to your question we confirm you that we are developing a stand alone D/A converter, that will be called InTransfer MKII.According to the tests we are carrying out, we state that this is a top quality machine with excellent performance. Following are the characteristics;32 bit - 192KHz - class A, tube (2x6H30)- fully balanced - SPDIF input - 2 usb ports to connect PC and portable devices.Price we suggest to end users is EURO 2.890,-- (w/out tax).At the present time we can not confirm you an exact date of availability as we depend on the long approval procedure of Apple."

 

[oldric_naubhoff]

How different would be the listening experience? I mean...what difference I might expect compared to a commercial DAC?

why spoiling the fun of finding out for yourself?

but seriously; if I or anybody else gave you some insight you might be looking for those traits when first listening to the device for the first time. in which case, I can assure you, you'd hear those traits.

it's better if you remain "tabula rasa" and listen to the DAC without any prejudice. if it's any better than Arcam DAC you'll have no problems to tell the difference. just a piece of advice. IME, the best material to test hi-fi device's merit is well recorded acoustic music, that you're well familiar with (most preferably something that you listened to on many systems, not necessarily hi-fi). if I recall well you like jazz. so you should find something suitable with ease in your collection .

 

[CnoEvil]

well, I just e-mailed Pathos and asked . they are very approachable company. I'm not quite sure if I can pass on the info but since they gave me that info it must not be too secret. so, here's what I know:
"With reference to your question we confirm you that we are developing a stand alone D/A converter, that will be called InTransfer MKII.According to the tests we are carrying out, we state that this is a top quality machine with excellent performance. Following are the characteristics;32 bit - 192KHz - class A, tube (2x6H30)- fully balanced - SPDIF input - 2 usb ports to connect PC and portable devices.Price we suggest to end users is EURO 2.890,-- (w/out tax).At the present time we can not confirm you an exact date of availability as we depend on the long approval procedure of Apple."

Thank you Sir

 

[acalex]

How different would be the listening experience? I mean...what difference I might expect compared to a commercial DAC?

why spoiling the fun of finding out for yourself?

but seriously; if I or anybody else gave you some insight you might be looking for those traits when first listening to the device for the first time. in which case, I can assure you, you'd hear those traits.

it's better if you remain "tabula rasa" and listen to the DAC without any prejudice. if it's any better than Arcam DAC you'll have no problems to tell the difference. just a piece of advice. IME, the best material to test hi-fi device's merit is well recorded acoustic music, that you're well familiar with (most preferably something that you listened to on many systems, not necessarily hi-fi). if I recall well you like jazz. so you should find something suitable with ease in your collection .

Yes indeed, I love jazz and everything which is acoustic (love unplugged cd of Eric Clapton for example). I have Pink floyd (Wish you were here and Dark side of the moon) in 24/96, the worst quality music I have is MP3 at 320Kbps. All the rest is either FLAC or 24/96. Don't have anything in 24/192 yet...pity

I am now upgrading the Arcam PSU with a 115 euro linear PSU produced for the rDAC which I found in the netherlands. They have 14 days refund policy and I am getting it shipped for free...so have time to try it at home and compare with a Rega DAC and send it back. So at least I can say I tried this one also. Next step would be getting the UDC1...mid november I guess... More on this, stay tuned and thanks for the advice!!!

 

[CnoEvil]

At the present time we can not confirm you an exact date of availability as we depend on the long approval procedure of Apple."

Ran this by my dealer, who confirmed that they were aware of this DAC. They were told that it could be available for Christmas...though they don't know how accurate this info still is.

 

[acalex]

At the present time we can not confirm you an exact date of availability as we depend on the long approval procedure of Apple."

Ran this by my dealer, who confirmed that they were aware of this DAC. They were told that it could be available for Christmas...though they don't know how accurate this info still is.

Are you also interested in feedbackless products?

 

[CnoEvil]

Are you also interested in feedbackless products?

Not because it's feedbackless per se, but because I like Pathos (which may be because it's feedbackless :? ).

 

[acalex]

Are you also interested in feedbackless products?

Not because it's feedbackless per se, but because I like Pathos (which may be because it's feedbackless :? ).

Do you have any pathos product? I just found out it's an italian company....if you want to buy it let me know cz I might be able to find cheaper in Italy (I am Italian). I found the M2Tech dac at 850 GBP...still wondering though... :rockout:

 

[CnoEvil]

Do you have any pathos product? I just found out it's an italian company....if you want to buy it let me know cz I might be able to find cheaper in Italy (I am Italian). I found the M2Tech dac at 850 GBP...still wondering though... :rockout:

Thank you Acalex, for the remarkably generous offer. I would worry that the Italian product would have the wrong voltage and plug. I also like the backup of a dealer, for when things go wrong, which for me, they usually do (I have a strong jinx!!).....but you never know.

I don't own a Pathos product, but like their amps and their Digit CDP. I went for the MF AMS 35i amp, but the Pathos Inpol 2 was nearly as good (IMO).

Cheers

Cno

 

[acalex]

Do you have any pathos product? I just found out it's an italian company....if you want to buy it let me know cz I might be able to find cheaper in Italy (I am Italian). I found the M2Tech dac at 850 GBP...still wondering though... :rockout:

Thank you Acalex, for the remarkably generous offer. I would worry that the Italian product would have the wrong voltage and plug. I also like the backup of a dealer, for when things go wrong, which for me, they usually do (I have a strong jinx!!).....but you never know. I don't own a Pathos product, but like their amps and their Digit CDP. I went for the MF AMS 35i amp, but the Pathos Inpol 2 was nearly as good (IMO). Cheers Cno

Plug for sure...voltage don't think so...are you from UK? If so we use 230V also...I am sure they can provide maybe with an UK plug...!
Regarding me in the end I decided to give it a try and ordered a linear external PSU for the Arcam rDAC on which I have 14 days return policy...I am also almost convinced about taking the feedbackless Linnenberg UDC1 DAC to try before end of the year (is 890 now isntead of almost 1300) as a trial...they claim to be a perfect match for the type of music I listen to...I might keep the rDAC anyway to plug notebooks through USB and tv/projector through coax and the UDC for fixed pc only (which is the main source of music)...I am really curios to feel the difference...

 

[paradiziac]

Do you have any name to suggest? To be honest I am not aware of any DAC which is feedbackless....

I know this thread is a little old, but I just saw it and it's very interesting.

I would just like to add that the Audio-gd NFB DACs are "No FeedBack", no op amps in the output stage. A cheaper option than some of the names listed.

To answer the poster who says that op-amps don't make a difference, I think if you had ever heard a pure class A amp like the Sugden A21, you wouldn't say that.

Yes, I'm a huge "Class A fan"! I think it's the best compromize between tubes and normal solid state gear. So clean and pure. It's without the digital harshness of mass market solid state or the wooliness of affordable tubes.