[ebag4]

I am currently running my Havana DAC into a F5 clone.  The Havana DAC  has a 2.6V output and <800 ohm output impedance.  The F5 has 100K input impedance.  I currently use the digital volume control through the USB connection but I would like to leave that at 100% and control volume through an analog control.

There is a Decware ZSLA-1 tube buffer stage preamplifier for sale near me so I am considering trying it out.  This will obviously give me volume control but what else will it do?  I do not want to add any sort of noise or hum into the system.  Are there any other pluses or minuses to be had with this combination?  The speakers used with this system are GR OB5 MTM sections with Hawthorne Audio Augies driven by their own amps operating from 200 Hz down.

Thanks for any insight you can offer.

Best,
Ed

[Quiet Earth]

The best way to retain the faithful sound of your DAC driving your amplifier, but be able to adjust the volume in the analog domain is to use a transformer volume control, or TVC. It sounds like you have plenty of system gain. You are already getting good results with the DAC driving the amp, and the amp driving the speakers. You are TVC ready.

You should do some searching for opinions on TVCs as well as other resistive based passive volume controls. Try to keep your perspective though because there are a lot of mixed results. Those results vary so much because not everyone has their total system optimized for a passive pre - whether its resistor based or transformer. Usually, the culprit is inefficient speakers and an amplifier that needs more than 1.5 volts in for full power out.

I love my TVC. I can't imagine ever going back to an active preamp. This is the one that I use :
http://www.diyhifisupply.com/?q=catalog/74/djangotvcpreamplifier

[Jon L]

I am currently running my Havana DAC into a F5 clone.  The Havana DAC  has a 2.6V output and <800 ohm output impedance.  The F5 has 100K input impedance.  I currently use the digital volume control through the USB connection but I would like to leave that at 100% and control volume through an analog control.

There is a Decware ZSLA-1 tube buffer stage preamplifier for sale near me so I am considering trying it out. 

Best,
Ed

Which "digital volume control" do you use in which software?  They are not all created equal, but the good ones will degrade the sound much less than your average volume pots or active preamps, unless you are attenuating massively.  I doubt that b/c F5 is a low-gain amp. 

Personally, if your system sounds good now, I would avoid it like the plague to add any additional "stuff." 

[Telstar]

I suggest you a LDR, that's the closest thing to the direct connection.
(search diyaudio for lightspeed)

[ebag4]

Thanks for the replies guys.  I am now debating whether or not to add another link in the chain. 

Gain; I probably need more headroom (which I realize the buffer will not offer) but the amp will play as loud as I typicaly listen.  Of course some albums are louder than others so some could use a bit more gain.  I appreciated the simple signal chain, I am getting a nice clean sound although not dry or sterile.  I dont want to add any noise to the system or degrade the sound so I would probably be looking a a fairly expensive (to me) preamp.

Which "digital volume control" do you use in which software?  They are not all created equal, but the good ones will degrade the sound much less than your average volume pots or active preamps, unless you are attenuating massively.  I doubt that b/c F5 is a low-gain amp. 

Personally, if your system sounds good now, I would avoid it like the plague to add any additional "stuff." 

JonL, I agree, I don't want to add any unecessary complexity to the system.  I am playing FLAC files via Foobar2000 with Xlobby as the UI, works very nicely with the thin client (iPaq PDA) acting as a remote with coverart and easy playlist generation.  How does Foobar's volume control stack up?  I have Xlobby set up for .5dB increments and rarely have to attenuate more than a few dB.

Best,
Ed

[Jon L]

Thanks for the replies guys.  I am now debating whether or not to add another link in the chain. 

Gain; I probably need more headroom (which I realize the buffer will not offer) but the amp will play as loud as I typicaly listen.  Of course some albums are louder than others so some could use a bit more gain.  I appreciated the simple signal chain, I am getting a nice clean sound although not dry or sterile.  I dont want to add any noise to the system or degrade the sound so I would probably be looking a a fairly expensive (to me) preamp.

Which "digital volume control" do you use in which software?  They are not all created equal, but the good ones will degrade the sound much less than your average volume pots or active preamps, unless you are attenuating massively.  I doubt that b/c F5 is a low-gain amp. 

Personally, if your system sounds good now, I would avoid it like the plague to add any additional "stuff." 

JonL, I agree, I don't want to add any unecessary complexity to the system.  I am playing FLAC files via Foobar2000 with Xlobby as the UI, works very nicely with the thin client (iPaq PDA) acting as a remote with coverart and easy playlist generation.  How does Foobar's volume control stack up?  I have Xlobby set up for .5dB increments and rarely have to attenuate more than a few dB.

Best,
Ed

Foobar volume control is very transparent IMO, especially if you're attenuating only a few dB's since you're not losing any resolution with Foobar's 32-bit processing.  In fact, if you're not using my favorite Foobar version 0.8.3 with Otachan ASIO, it may be worth seeking out (try emailing audioengineer) as the next significant sonic upgrade. 

I would only consider a preamp in your case if your system needed extra "kick" and drive in the bass, in which case Pass B-1 buffered preamp may be added to your list. 

[ebag4]

Thanks JonL,
I have DL'd 0.8.3 and the Otachan ASIO files (both 47a and 51 as noted in your post on AA).  I have loaded Foobar and inserted the ASIO .dll under Foobar2000>components and set up ASIO .dll in preferences but the output cannot be found and the ASIO isn't loading.  Is there a step I am missing?  Thanks for any help you can offer.

Best,
Ed

[Jon L]

That's probably because you are using the USB connection to your DAC.  The Havana uses the C-Media USB chip, and I do not believe it supports ASIO via Foobar. 

As with most "USB DAC's," the Havana probably sounds better with a good spdif/coax anyway, but if you're stuck with USB, you could install ASIO4ALL and use that with Foobar.  It'll sound better than non-ASIO4ALL USB input. 

[ebag4]

Thanks Jon,
Yes, I just noticed that my DAC is working but it is not availablr as a sound device.  I have been using the ASIO4ALL with no issue.  I will reload that and see if it comes back up.

Best,
Ed

[jrebman]

Ed,

Where did you get the 0.8.3 version of foobar?  How's it working with ASIO4 all?

Bet you can't guess why I'm asking .

-- Jim

[ebag4]

Hi Jim,
Oh, I might be able to guess  .  I did not have any luck with 0.8.3.  From what Jon L tells me the USB chipset that is used with the Havana isn't compatible with ASIO via Foobar.  I have read that the .9 and up revisions of Foobar use ASIO4ALL and can't use the ASIO plug-in as the previous revisions did.  I couldn't get 0.8.3 to see the ASIO4ALL unless I installed the ASIO .dll in Foobar2000>Components folder, then it saw the ASIO4ALL and would play, not via USB but on my laptop that I log onto my server machine with.  It may be that 0.8.3 isn't truly compatible with ASIO4ALL for the same reason that later revisions can't use the ASIO plugin, I don't know for certain and don't really have time to play with it.  I seem to recall that you are not using USB so it is possible that 0.8.3 would work fine for your application.  Here is where I found 0.8.3:  http://foobar2000.brothersoft.com/foobar20000.8.3
It is at the bottom of the page.

This is where I found the 51 and 47a Otachan ASIO plugins that Jon L likes:  http://personales.ya.com/angel49/foobar2000_otachan/intro.htm

It may work for me if I messed with it but for now I am back to Foobar2000 9.5.1 and ASIO4All.

Take care,
Ed

[jrebman]

Ed,

Thanks, that saves me some hassles for sure.  Actually, I'll be using pretty much nothing but USB with the Havana now.  I'm getting a preamp and the transport has no place to live anymore, so it and the Audio Sector sp/dif dac will be going -- no room in either system to physically put them, so my office system will just use the Havana with my Acer Aspire One netbook from here on out.

You know, I actually did this on purpose -- had a small, sturdy, attractive rack made that only has two shelves -- one for sources and preamplification, and the other for the amplifier(s), so I would force myself to keep things simple and uncluttered.  So far the strategy seems to be working, and with the netbook and the fileserver, I'll al most never use a physical CD except to rip it to the server.

Besides, foobar works quite nicely, right out of the box, with my screen reader, which makes it quite easy to use.  One of these days I'll finish configuring and scripting to make Media Monkey that accessible, and when I'm happy with that, will probably switch over as the library and other features are somewhat more sophisticated for both me and for Linda.

Take care,

Jim

[dweekie]

I consistently kept my Foobar2000 up to date for many years.  After reading this thread, I decided to backtrack to 0.8.3 again.  Wow, I'm surprised the sound is consistently better to my ears.  I'm sticking with 0.8.3 now (asio 0.51.7 dll, modded cmedia 8788 soundcard with AK4396 passive-out). 

[Quiet Earth]

debating whether or not to add another link in the chain. 

What about taking out a link?  Every time you have to change, recalculate, or transfer the digital signal you have just taken a non repairable step away from the original music. The less calculating and manipulation that you do in the digital domain the better. I know I'm in the minority on this one because once you are in the digital domain, you are supposed to be free to do whatever you want without consequence. I think that's where all of the real damage is done.

Some day you might want to hook a component up that has analog outputs. It's nice to be able to do that too.

[IronLion]

I would only consider a preamp in your case if your system needed extra "kick" and drive in the bass, in which case Pass B-1 buffered preamp may be added to your list. 

I just received a B-1 the other day to use between my MW Transporter and my Spectron amp.  It definitely seems to add more kick and so far I'm happy with it.  I have a pair of EVS Ultimate Attenuators that you could use in your particular situation, though they're not remote-controlled if thats an issue. 

[ebag4]

debating whether or not to add another link in the chain. 

What about taking out a link?  Every time you have to change, recalculate, or transfer the digital signal you have just taken a non repairable step away from the original music. The less calculating and manipulation that you do in the digital domain the better. I know I'm in the minority on this one because once you are in the digital domain, you are supposed to be free to do whatever you want without consequence. I think that's where all of the real damage is done.

Some day you might want to hook a component up that has analog outputs. It's nice to be able to do that too.

Hi QE,
I am not certain I understand whether you are advocating adding a preamp or not but I can tell you that my setup is currently as minimalist as you can get:
Computer>DAC (via USB)>Power Amp>Speakers
I can't remove any links.  With regard to adding an analog device in the future, I probably won't  .  I have tried incorporating a vinyl setup a few times but my collection is small and I would have to spend more than I am willing to to best my current digital setup.

With regard to being able to do anything in the digital domain without penalty, I don't believe this is acurate.  It is my understanding that once you attenuate too much in the digital domain you begin to remove data from your signal.  In my system my amp is of low enough gain (F5 Clone) that I attenuate very little to reach my normal listening SPL, of course the flip side of that is that I have very little headroom left from my amp.  That is really where I am going back and forth, do I want to increase gain in the ampification section or do I leave well enough alone and enjoy what I have?  Of course that may be the most difficult part for most of us on this site, leaving well enough alone .

Thanks for the response.

Best,
Ed

[ebag4]

I would only consider a preamp in your case if your system needed extra "kick" and drive in the bass, in which case Pass B-1 buffered preamp may be added to your list. 

I just received a B-1 the other day to use between my MW Transporter and my Spectron amp.  It definitely seems to add more kick and so far I'm happy with it.  I have a pair of EVS Ultimate Attenuators that you could use in your particular situation, though they're not remote-controlled if thats an issue. 

Hi Iron Lion,
Can you tell me what you attribute the additional "kick" to?  Do you believe it is the impedance matching the buffer supplies or are you finding that there is actually some gain added by the B1?  Given my source (Havana DAC's <800 ohm output impedance) and my amp (F5's 100K input impedance) it is my understanding that a buffer should not be necessary.  With that said I am not certain I fully understand why but that is what I have gathered through reading some of the DIY Audio forums.  This is why I started this thread, I was wondering if a zero gain buffer would add additional kick or headroom because of the impedance matching even though the buffer is zero gain.

Best,
Ed

[IronLion]

The B-1 does not have any gain, so I'm attributing all the additional "kick" to the low output impedance of the buffer, which I'm guessing is substantially lower (B1's is 2000ohms) than the output impedance of the MW Transporter (Dan hasn't measured specs on this yet I believe).  In your case I was surprised at how low the output impedance of your DAC was and yeah I agree, it wouldn't seem that you would benefit in any way from a buffer like the B-1, but, if you are interested in trying it it would basically give you what you're looking for (a transparent volume control) and perhaps even add some more dynamics to your music (who knows?), in addition to giving you a channel balance control, which for me was important to have in my room as the image leans heavily to the right.  Mark at Reno HiFi is great to deal with and is offering an introductory price on the B-1 as well as a 30 day satisfaction guarantee.     

In the end, there's only one way to find out I guess.  One thing to consider as far as my remedial understanding of all this goes is that the B-1 has the 2000ohm output impedance and delivers that throughout the audible frequency range; though your DAC's output impedance is measured as 800ohms or so, that could only be at a particular frequency unless its specified by the manufacturer, so who knows, there may be some gains to be had by putting a buffer in between it and your amp.   

[ebag4]

The B-1 does not have any gain, so I'm attributing all the additional "kick" to the low output impedance of the buffer, which I'm guessing is substantially lower (B1's is 2000ohms) than the output impedance of the MW Transporter (Dan hasn't measured specs on this yet I believe).  In your case I was surprised at how low the output impedance of your DAC was and yeah I agree, it wouldn't seem that you would benefit in any way from a buffer like the B-1, but, if you are interested in trying it it would basically give you what you're looking for (a transparent volume control) and perhaps even add some more dynamics to your music (who knows?), in addition to giving you a channel balance control, which for me was important to have in my room as the image leans heavily to the right.  Mark at Reno HiFi is great to deal with and is offering an introductory price on the B-1 as well as a 30 day satisfaction guarantee.     

In the end, there's only one way to find out I guess.  One thing to consider as far as my remedial understanding of all this goes is that the B-1 has the 2000ohm output impedance and delivers that throughout the audible frequency range; though your DAC's output impedance is measured as 800ohms or so, that could only be at a particular frequency unless its specified by the manufacturer, so who knows, there may be some gains to be had by putting a buffer in between it and your amp.   

Thanks for the reply IronLion.

Best,
Ed

[Quiet Earth]

Hi Ed,
Sorry for the confusing reply. An analog volume control is the way to go in my opinion.  Every time you manipulate, redirect, or adjust the digital signal you lose something. Why not leave it alone as best as you can? If you remove the destructive method of controlling the volume digitally,then you remove a big link in your system.

Also, since the output of your DAC is analog, then you do have an analog source. You are more in the analog domain than you care to think.

Let's forget all of that for a moment and move on to something more important. We just learned :

 
In my system my amp is of low enough gain (F5 Clone) that I attenuate very little to reach my normal listening SPL, of course the flip side of that is that I have very little headroom left from my amp.

Now that's a huge piece of information. I guess I missed it the first time. You will get poor results with any type of passive analog volume control because you don't have enough system gain. A TVC in particular works best when its attenuating at a minimum of 14 dB. It sounds to me like you only need a few dB of attenuation. An active (or buffered) line stage would be the best for you, should you decide to go that route.

It's gonna be hard to find a transparent line stage for under a grand.