[orpheus]

I know you're a very busy guy, and I hope I'm not annoying you by asking about this, but I'm wondering if there is any news about the Chime DAC you mentioned last fall.   Any information would be appreciated, as I am trying to decide how I want to upgrade/change my digital setup.  I've built a Bugle and a Bugle power supply, and am very impressed with your work and the value it represents.  

Thank you for your time-
Aaron.

[hagtech]

Orpheus,

Right now the CHIME dac design is on the back burner.  Difficult to maintain progress with so many projects in the works.  I'm sort of back to wondering if I missed the market window on this one.  At this point in time, who needs a tube DAC?  Or perhaps I should ask, with all the new SACD and universal players coming out, isn't that what folks will spend their money on?  If so, then a non-SACD, non-DVDA dac becomes rather obsolete.

Someone mentioned USB is the way to go.  Use a PC as the storage/retrieval mechanism.  Then connect high quality DAC via USB.  Wavelength Audio has one.  I think Sutherland designed one too.

I guess I'm just not in tune with the digital crowd.  Not sure where it is going.  Or if anyone (more than a few) wants to spend money on just a CD dac.  A few years back I think it would have been perfect.  For me, it's a lot of work to do such a design, and I need to get that ROI.

Meanwhile, a number of other projects eat up available time.  I tend to focus on what I am excited on at the moment.  Right now, it's a 6-channel surround preamp.  All tube.  Just finished the OBOE.

jh

[BradJudy]

Right now, it's a 6-channel surround preamp. All tube.

You mean like a 6 channel tube linestage for between a pre/pro and an amp or something with gain designed to go between the multichannel player outputs and the amps?  

I guess it depends if you intend for the item to do double-duty for multichannel audio and movies.

[hagtech]

Yeah, six tube channels, each with gain trim, plus master volume.  Also includes matrix decoder to convert stereo inputs to psuedo-surround (the old Hafler trick).  And all in tubes.

Not sure if there is a market for this yet, but I can forsee one coming.  This flexible linestage has two 6-channel inputs and three stereo inputs, so it bridges between full surround systems and legacy stereo/mono.  So instead of using digital volume controls, or pumping quality audio through your mass-market DSP linestage/video/control center, you take the DVDA and SACD analog outputs into an analog linestage.  Volume is now analog with no manipulation of the digital data.  

Have the circuit designed, still trying to locate OEM sources for volume and select switches.  I do not want to use relays or MDACs or other "digital" forms of volume control.  Rack-wide chassis 12 inches deep, tubes and transformer and chokes all inside.  

So yeah, double-duty.  For folks slowly upgrading from stereo to surround.  You can do it in pieces.  No worry about future compression protocols or bitstreams or encoding.  Analog will always be analog.  I figure not everyone can afford separate audio and home theater installations.  May as well start converging now.

jh

[BradJudy]

Jim,

I don't know what market there is for that.  I guess I tend to think that most people who want multichannel have it already and was thinking of how it would best integrate with an existing multichannel system.  

Since most amps are single input, I was thinking of it as something like a line stage/tube buffer that would go between the 6-channel DVD-A/SACD output and the multichannel input on a pre-pro/receiver.  

It sounds like you are thinking about bringing the idea of a traditional tube pre-amp to an audio only multichannel system.  I haven't yet met anyone with an audio only multichannel system, but I'm sure there are some out there.  

One issue with a multichannel tube pre-amp is that you are reliant on the bass management of the source (which is usually very limited), or you have to place an additional item in the chain (like an ICBM) to handle BM.

[orpheus]

Jim-
     I think your plan for a six channel analogue all tube preamp is great.  I don't think there are many such products available, especially tubed.   The Oboe looks like an excellent deal, I would have probably built one instead of just a bugle if it was available when I ordered my bugle board.

I understand where you are coming from with doubting the marketability of a CD only DAC.  However, I don't think that you've missed the market on a tube dac.  Some of the reasons you state for people not needing a tube dac could be exactly why they need one.  Two channel 44.1khz/16 bit audio is here to stay, whether we like it or not.  There are very few releases in SACD or DVD-A compared to what is available in redbook, which means that we will be listening to redbook for a long time to come.  The output stages and power supplies on the all in one digital players are often compromised or poorly designed.  Higher resolution formats can still sound good (relative to redbook) with a compromised design, but redbook suffers, perhaps because it is more mature and we know more of it's capabilities.  So, if you want to have good sound with both SACD/DVD-A and redbook, the best solution might be to buy a universal player, and add a DAC with a better power supply and output stage than what's inside your player.  I'm not convinced that a player that plays everything could be as good as a well designed outboard DAC, especially when you consider the noise from the video circutry, and building to a price point and having to put so much into a player.  Reviews of universal disc players rarely praise their redbook performance.

Then there is the question of computer as transport.  Many people on the audio boards (I frequent AA and DIYaudio more than AC), claim that the sound from a hard drive as transport is better than using a CD only transport of excellent quality.  I have been considering using a hard drive as a transport, because I have a lot of music stored in apple lossless to play on my ipod.  In order to do that with few sonic compromises, I need to have an external DAC.  Whether or not USB is superior is up for debate,
and many people report success with a toslink or usb to spdif converter.  The success of the ack! dack, as well as rising prices of used DACs on audiogon (I know because I spend far too much time looking at prices there) indicate that there is at least still interest in stand alone DACs, esp. below $1000 or so.  

There are also modders who are getting high praise for putting tube output stages and new/modified power supplies into multiformat players.  If you haven't read it, here's a very glowing review of Dan Wright's work:

http://www.positive-feedback.com/Issue14/modwright999ES.htm

I think that a DAC designed and voiced by an excellent engineer with good modern processor and well designed power supply coupled with a simple tube output stage could kill the sound available from the opamps and switching power supplies that are usually in the multiformat players.


Thanks for taking the time to read my message.

-Aaron.

[hagtech]

Ok, so maybe there still is interest in a DAC.  I'd really like to do it too.  Just never know which product will be hit or miss.  Hard to get ROI on 1/2-kits.  For example, I don't think I'll ever sell enough Cymbal circuit boards to make up for the time I spent designing it.

So I will move DAC higher up in priority.  Started design with the DIR1701 chip, then bang!  They obsoleted it.  Whew, that was close.  Will have to find a way to use a Crystal receiver.  The thing is, I plan to re-clock with a low noise PLL for jitter reduction, would have been easier with the 1701.

Maybe I better check out home theater market a bit more too.  Maybe I need a bypass mode?  Would like to be one of the first on the block with such a machine.  So far there is the super expensive Fosgate;  McCormack has a nice SS one.  My tube version will be similar, but probably better sounding and cheaper.  There is also the new Meitner.  I think the need is for a non-DSP volume control with channel trim (room setup) and input select.  Am I missing something?

jh

[MaxCast]

Am I missing something?

A remote  

I should add, there are a few CD's out there which people will be listening to for many more years.  SACD/DVD-A can die any minute.  Also keep in mind that universal players may sound well and dandy in SACD/DVD-A but lack in redbook.  At least the lower players I have heard do.

[hagtech]

I'm a little torn on the remote control issue.  Thinking it would be nice, but doesn't fit the retro/vintage/simplicity feel of the product line.

Is remote for volume enough?  Or must it also do input select and channel gain trims?  

jh

[mcgsxr]

Having had Mike G add a remote volume to my Clarinet, I would say that just volume is perfect...

Then again, I only have 1 source - well, 2 if you count the HT bypass, but really, that I am happy to go and engage.

So I would say that a remote for volume is great, especially with a mute button, like mine!

[MaxCast]

I'm a little torn on the remote control issue.  Thinking it would be nice, but doesn't fit the retro/vintage/simplicity feel of the product line.

Is remote for volume enough?  Or must it also do input select and channel gain trims?  

jh

 
I thought a remote would be out ot the question.  I have seen a lot of preamps I would like to try that only control volume.  I'm a bit different in that I like to listen to music while watching a game or two on the tubes.  The ability to switch to a different source on the fly with out moving my ass is a bonus in my book.

I agree with BradJudy.  I hate being held hostage by BM issues handled incompletely by the player.  In fact, I'm about ready to ditch my 5.1 preamp and get a receiver for 5.1 and a 2ch preamp with HT pass through and remote.

It's interesting your thought on adding a matrix decoder.  I don't know of Haflers bag of tricks but my 5.1 preamp is only stereo.  I'd be nice to have a good surround mode for video.   I read McCormack's is not that good- don't know for sure.

Back to the topic.  I think you'd sell many more DACs than preamps....unfortunatly.

[bluesky]

Hi Jim (and others)

I would have to chime in (haha) on supporting a DAC.  Here in Australia SACD's and DVDA's are nonexistent except through specialty internet suppliers.  I have regularly asked large music stores about them and not one staff member has even known of their existence let alone the general public.

This leads me to believe that Redbook CD's will remain the main music source for most of us.  When I recently decided on a new front end I got a record player (Michell Gyro SE) and a redbook CD player.  These were bought for lifetime use and I figure most people's music collection won't be readily replaced for a long time, if ever.

It is interesting to note that LP's are still going strong, I think CD's will too!

Ian

[hagtech]

Ok, so you guys convinced me there will still be a CD and DAC market for a long time to come.  It does make sense, if you look at history.

The CHIME is something I always wanted to do.  Heck, I even went out and bought a CD player just to have a transport.  Need to come up with a good circuit for re-clocking data right after receiver, without spending a bundle.  

Will put this project back on top.

jh

[Adinoto]

Jim,

I also agree that we need good DAC. I have sony universal player and it'sit's realy far from my vinyl quality (which use your bugle, thanks).
How about non over sampling simple dac with TDA 1543 or 1541, tube buffer, usb and spdif input so it can be used with computer or/and universal players. That's my dream...

regards

[bluesky]

Dear Adinoto

Yes I would have to agre with your wish list.  But this is only from what I have read, not what I have experienced!

What I find quite amazing is that those in the retail end of music have no knowledge of the hires products at all.  This just confirms to me that the Redbook CD's will be around for quite some time.

One review I read recently summed it up well.  The reviewer stated that he did not believe either SACD or DVD-A will survive and in addition to this the current development of CD players is just getting better and better with a lot of ongoing development contniuing on CD players.  It is now at the point where good Redbook players are often just as good, if not better than their Hires counterparts.

This is just an idea but I have read a few of the posts regarding the CDPRO transport kit that is now available.  It would be good if Jim could design his DAC to mesh in with this kit.  This would provide a really high quality transport with Jim's DAC and provide a ready chassis and transport to compliment the DAC.

This would I believe make Jim DAC a better marketing proposition for us DIY's and let's face it that is the market that Jim caters to.  Making it easy to complete a project with readily available cases and a transport woud make the idea much more appealing to many I believe.

Cheers

Ian

[hagtech]

Ian, do you have a link to the CDPRO?

And I thought the TDA1541 type chips were no longer available?  I'm not a fan of the non-oversampled variety.  They spew way too much ultrasonic trash that can really mess up things downstream.  I prefer to output a very clean and well behaved signal.  Brickwall filter is out of the question.  Will use a Bessel type phase linear filter, probably 3rd order.  

Thinking about the USB connection.  Will have normal RCA S/PDIF input.  Forget the Toslink.  Imagining most people won't have a computer that close to their audio rack.  USB cables aren't that long.  But you can make the RCA cable real long.  Looks like there are some sound cards or adapters that convert USB to s/pdif output.  Then maybe I don't need to include?

Also, can I fix this DAC at 44.1k redbook?  My re-clocking scheme doesn't really want to be multi-mode.  I can do it, but I'd rather keep phase noise (jitter) to a minimum.  Is USB sound 48k (dang, I'm such an analog-only guy)?

Yeah, that would be cool, putting a transport and tube dac into your own box!

jh

[bluesky]

Hi Jim

The CDPRO is available from Ken at DIY Zone on this forum and through the DIY Zone in Taiwan.  I will find the links for you and email them on to you.  There is also Daisy Link in the Netherlands (from memory I could be wrong) who also sells the CDPRO stuff.  You could also try Philips directly but DIY Zone in Taiwan could supply the case and bits and pieces to make it a complete package.

Obviously this is something you would need to work out with the various suppliers but my guess is that the Taiwan connection could tailor a package with the transport, case and your DAC.  It does seem possible to me and would be just the ticket for us DIYers.

Cheers

Ian

[Adinoto]

Hi jim,
I once read in the net that there is some usb extension cable up to 10m or more.
Also think that your DAC might be used as upgrade to those crapy soundcard? If the project is simple enough like Bugle, I belive a lot of people would interested just to used it as second system with their computer. A lot of audiophile is also computer geek eh..

cheers

[hagtech]

Well, it won't be as simple as Bugle.  Or maybe.  Seems all the parts I want to use are surfasce mount.  So I'm thinking to make a daughter card with DAC that plugs onto a CHIME motherboard.  The power supplies & tube circuits and connectors, etc on the main board.  So maybe 1/2 DIY?  The surface mount card would have to be preassembled & tested.  

I could also make a SS verion in an OBOE style box.  Same daughtercard.

Could use the PCM2704 USB-to-SPDIF IC.  Worried that this violates the KISS principle and worries me a bit.  Too much stuff in one bite.  The idea is that the CHIME DAC works with any cheap transport, including cheap sound cards with SPDIF outputs.  As long as jitter is less than +/-50% peak of clock cycle.  The CHIME will not have it's own clock, but instead a very slow responding PLL that tracks the input.  The PLL tracks the transport clock below audio frequencies, and rejects any jitter above, say 20Hz.  Sort of like a heavy flywheel on a turntable driven by a squirrel.  And get this, a meter that shows jitter & tracking error in real time!  Redbook only.

So far, I'm looking at a CS8415 receiver with two inputs (one for transport, the other for sound card).  Then a custom ECL PLL circuit (that's the easy part) into a DF1704 and pair of PCM1704 dacs.  The dacs are terminated in low value resistor (I-to-V converter) and 3rd order LC filter into an SRPP like the CLARINET.  No feedback.  Special considerations all around for power supply filtering and power planes.  

Maybe I'll make the output section differential with XLR connectors?

jh

[BradJudy]

Jim,

I'm thinking of getting a few of these simple PCM2902 boards to play with.  Something like this might be a good idea for those looking for USB support to add on their own (or perhaps you could have a second USB input daighter card option )

http://www6.head-fi.org/forums/showthread.php?t=109671

Brad