Is the TubeDAC-11 passive or active as a preamp?
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iGrant
Grant Fidelity Forum Moderator
Hi Woody,
This is my answer to basically the same question in another forum:
To answer some questions posted here and from emails (thanks for writing us)
The TubeDAC-11's maximum output is 6V RMS thru the Tube and Line outputs, 2V RMS on the DAC Direct Out. The entire output stage was tweaked to death to make a volume control that can be used for the various scenarios the TubeDAC-11 will likely be used in as well as the multitude of tubes that can be rolled in and the 5 sources that can be hooked up and basically turned into Tube sources:
1. As a traditional DAC The Volume Knob sets Tube and Line Outs to the right level for your pre-amp or integrated from the 5 sources (typically 1/2 to 3/4 volume, with 3/4 typically being about 2.5v) I find that with my gear just under 3/4 volume is where I like it, probably just over 2v. The DAC Direct of course has no volume control and only the 3 digital inputs comes out the DAC Direct Out. I expect most will use both the DAC Direct Out and the Tube Out to their pre-amp stage and switch between to suit your music library selection and sources. I run all 3 outs at the same time into my pre-amp stages on my systems, always fun to be able to get 3 flavours of sound at the switch of your pre-amps input control. We found that adding a switch to take the volume control out of the circuit was more of detriment to the sonics than have the volume control always present ! Plus you can always run the DAC Direct out Thru something like the B-283MKII loaded up with the Treasure CV181-Z or your favourite 6SN7 for a whole new world of high-end TubeDAC. Or run the DAC Direct Out to a dedicated headphone amp, which can sometimes be difficult incorporate into a system without manually switching cables around.
2. As a standalone pre-amp the TubeDAC-11 is vastly improved over the 09 in that the range of the volume is much expanded, with vintage amps that produce full power at typically 1v, you will likely get to half volume before your amp clips, with more modern amps that range from 1.5 to 2.5 v to develop full power, you will get closer to 3/4 volume before clipping, for more stubborn amps that need lots of drive, the TubeDAC-11 is quite capable up to full volume. The 11 is designed to be a pre-amp, the 09 it was potential feature that many had success with, some didn't have enough volume range and were done at under 1/4 volume, some didn't have enough output to make their amps make any volume. If we put the 11 in a big box and threw in a remote your would think you have a $1k+ pre-amp . For the price range we were after, no way can you get a remote inside that doesn't screw around with the sonics. You can get all of that in my W-30 amp. You of course have the Line Out for bi-amping or running subs, Typcally the Tube Out will run the top end and SS Line Out will run the bottom end or sub.
3. As a standalone Headphone amp, both tube and SS. The 09 was a fluke that we could run some headphones of the back RCA tube outputs, for the 11 this was designed in so that both front (SS) and back (Tube with RCA to headphone jack adapter) will drive just about any normal headphone design out there, again giving a useful volume control range.
4. Computer Audio, Home Theatre, Recording Studios all bring lots of other requirements that the TubeDAC-11 can (hopefully) handle and most of this because of volume control design.
When setting the TubeDAC's volume control as a DAC to your pre-amp stage I suggest using the DAC Direct out as your reference to see where the TubeDAC-11's volume control matches that, just switch between the two outputs on your pre-amp. Then do some careful listeing as to where the Tube Out volumes starts to sing with your system, for low power SET amps I find a little boost helps a lot, for big power I find backing off relaxes the system a lot, experiment and you will find that you can the right synergy between the TubeDAC-11 and just about anything out there.
Hope that helps,
Ian
This is my answer to basically the same question in another forum:
To answer some questions posted here and from emails (thanks for writing us)
The TubeDAC-11's maximum output is 6V RMS thru the Tube and Line outputs, 2V RMS on the DAC Direct Out. The entire output stage was tweaked to death to make a volume control that can be used for the various scenarios the TubeDAC-11 will likely be used in as well as the multitude of tubes that can be rolled in and the 5 sources that can be hooked up and basically turned into Tube sources:
1. As a traditional DAC The Volume Knob sets Tube and Line Outs to the right level for your pre-amp or integrated from the 5 sources (typically 1/2 to 3/4 volume, with 3/4 typically being about 2.5v) I find that with my gear just under 3/4 volume is where I like it, probably just over 2v. The DAC Direct of course has no volume control and only the 3 digital inputs comes out the DAC Direct Out. I expect most will use both the DAC Direct Out and the Tube Out to their pre-amp stage and switch between to suit your music library selection and sources. I run all 3 outs at the same time into my pre-amp stages on my systems, always fun to be able to get 3 flavours of sound at the switch of your pre-amps input control. We found that adding a switch to take the volume control out of the circuit was more of detriment to the sonics than have the volume control always present ! Plus you can always run the DAC Direct out Thru something like the B-283MKII loaded up with the Treasure CV181-Z or your favourite 6SN7 for a whole new world of high-end TubeDAC. Or run the DAC Direct Out to a dedicated headphone amp, which can sometimes be difficult incorporate into a system without manually switching cables around.
2. As a standalone pre-amp the TubeDAC-11 is vastly improved over the 09 in that the range of the volume is much expanded, with vintage amps that produce full power at typically 1v, you will likely get to half volume before your amp clips, with more modern amps that range from 1.5 to 2.5 v to develop full power, you will get closer to 3/4 volume before clipping, for more stubborn amps that need lots of drive, the TubeDAC-11 is quite capable up to full volume. The 11 is designed to be a pre-amp, the 09 it was potential feature that many had success with, some didn't have enough volume range and were done at under 1/4 volume, some didn't have enough output to make their amps make any volume. If we put the 11 in a big box and threw in a remote your would think you have a $1k+ pre-amp . For the price range we were after, no way can you get a remote inside that doesn't screw around with the sonics. You can get all of that in my W-30 amp. You of course have the Line Out for bi-amping or running subs, Typcally the Tube Out will run the top end and SS Line Out will run the bottom end or sub.
3. As a standalone Headphone amp, both tube and SS. The 09 was a fluke that we could run some headphones of the back RCA tube outputs, for the 11 this was designed in so that both front (SS) and back (Tube with RCA to headphone jack adapter) will drive just about any normal headphone design out there, again giving a useful volume control range.
4. Computer Audio, Home Theatre, Recording Studios all bring lots of other requirements that the TubeDAC-11 can (hopefully) handle and most of this because of volume control design.
When setting the TubeDAC's volume control as a DAC to your pre-amp stage I suggest using the DAC Direct out as your reference to see where the TubeDAC-11's volume control matches that, just switch between the two outputs on your pre-amp. Then do some careful listeing as to where the Tube Out volumes starts to sing with your system, for low power SET amps I find a little boost helps a lot, for big power I find backing off relaxes the system a lot, experiment and you will find that you can the right synergy between the TubeDAC-11 and just about anything out there.
Hope that helps,
Ian
iGrant
Grant Fidelity Forum Moderator
Hi Woody,
It is still technically a passive pre, there is no current gain, the voltage is fixed in the output stage and the volume control passively reduces the voltage. By adding the TubeDAC-11 in front of a pre-amp you are not creating two pre-amps, you pre-amp is seeing the TubeDAC-11 as a line level source that just happens to have a volume control. Kind of like tapedecks back in the day or a CDP with volume control.
Cheers,
Ian
It is still technically a passive pre, there is no current gain, the voltage is fixed in the output stage and the volume control passively reduces the voltage. By adding the TubeDAC-11 in front of a pre-amp you are not creating two pre-amps, you pre-amp is seeing the TubeDAC-11 as a line level source that just happens to have a volume control. Kind of like tapedecks back in the day or a CDP with volume control.
Cheers,
Ian
ictwoody
I like vintage gear — my preamp is from 2007.
Thanks for the clarification, Ian. I think I am going to try a TubeDAC-11 as a dedicated pre for a new-to-me Cary SLA-30 (EL84 based) poweramp I just purchased. There just isn't any tube or hybrid pre's out there that can touch you're Dac-11's feature set for the money. Since my sources are a phono-pre, Apple MacMini, and a Sony HD Tuner the two analog inputs and the optical input are perfect for me. I can even add a CD player with the coax later if I need to.
I have been very happy with my two TubeDac-09's and since I would need a DAC as a source anyway I just don't see a better option out there.
I will be ordering very soon.
Thanks again for your help,
Woody
I have been very happy with my two TubeDac-09's and since I would need a DAC as a source anyway I just don't see a better option out there.
I will be ordering very soon.
Thanks again for your help,
Woody
etocynned
Active Member
Ha Ha Ian! Did you know I'd be watching this thread?
Dac11 is may next planned purchase.
iGrant
Grant Fidelity Forum Moderator
You can just turn the 09's volume control to max for 2.3v output, sounds identical to converting to DAC mode. Still suggest with the 09 you try different volumes going into the pre.
Cheers,
Ian
Thank you sir.
ictwoody
I like vintage gear — my preamp is from 2007.
Okay. So to be honest I'm still sorting out my system and I haven't actually hooked my new GF TubeDAC-11 up to the Cary yet, but I have a question. The manual for the SLA-30 lists the input sensitivity at 0.625V for full output.
If that's the case won't my volume control on the 11 be a bit limited?
**edit**
Should I build a custom interconnect to go from my DAC/PRE's output into the Cary - like this?
http://audiokarma.org/forums/showthread.php?t=392186
- Woody
If that's the case won't my volume control on the 11 be a bit limited?
**edit**
Should I build a custom interconnect to go from my DAC/PRE's output into the Cary - like this?
http://audiokarma.org/forums/showthread.php?t=392186
- Woody
iGrant
Grant Fidelity Forum Moderator
Hi Woody,
I suggest trying without first and see if you have a usable range, most vintage gear only gave you less than half of the volume knob for control and see if you have enough control. My guess is you will be just under half volume for full power with your Cary which is kind of on the very low side. The TubeDAC-11's volume comes on slow from zero so I think you will be fine.
In line attenuation is always an option, DIY or off the shelf, you will need to use your ears to see if the pro's of using them (more control, better pre to amp matching) out weigh the potential con of slightly reduced fidelity by having another circuit in the chain.
Do let us know how it works for you and as always, but especially in your case (modern higher voltage pre into older low voltage amp) shut down the amp first then the TubeDAC-11 when shutting down your system, and turn on the TubeDAC-11 first then the amp when powering up.
Cheers,
Ian
I suggest trying without first and see if you have a usable range, most vintage gear only gave you less than half of the volume knob for control and see if you have enough control. My guess is you will be just under half volume for full power with your Cary which is kind of on the very low side. The TubeDAC-11's volume comes on slow from zero so I think you will be fine.
In line attenuation is always an option, DIY or off the shelf, you will need to use your ears to see if the pro's of using them (more control, better pre to amp matching) out weigh the potential con of slightly reduced fidelity by having another circuit in the chain.
Do let us know how it works for you and as always, but especially in your case (modern higher voltage pre into older low voltage amp) shut down the amp first then the TubeDAC-11 when shutting down your system, and turn on the TubeDAC-11 first then the amp when powering up.
Cheers,
Ian
ictwoody
I like vintage gear — my preamp is from 2007.
Thanks for the tips Ian. I'll give it a whirl as soon as I find time and see what I think.
- Woody
- Woody
PerfectDrug
Active Member
Can it be used as a pre amp and dac via toslink at the same time?
ictwoody
I like vintage gear — my preamp is from 2007.
So Woody, have you had a chance to test it? If so, do you get good results without attenuators? I'm interested because I consider getting a tubedac-11 and use it as a preamp (once I fix a few other things in my system).
I am convinced that there is no better preamp/DAC bargain even now than the Tube DAC 11. I am using it as the main preamp for my Classé CA-100 power amplifier and could not be more pleased with the sound. I've had this for a couple of years, and I have a Voskhod Rocket tube in it now.
My Thorens 124 running to the Lehmann Audio Black Cube phono pre then the TD-11 just sounds sublime! I'm using both analog inputs, the optical digital from my CD player (used as a transport except for SACD which is hooked up analog). USB to SPDIF from my computer. The sound is open and airy, I'd like to put it up against a more expensive tube preamp, just for fun, but I can't imagine a huge improvement... Hats off to Grant Fidelity for creating a highly affordable piece of equipment that takes the masses into the high end!
My Thorens 124 running to the Lehmann Audio Black Cube phono pre then the TD-11 just sounds sublime! I'm using both analog inputs, the optical digital from my CD player (used as a transport except for SACD which is hooked up analog). USB to SPDIF from my computer. The sound is open and airy, I'd like to put it up against a more expensive tube preamp, just for fun, but I can't imagine a huge improvement... Hats off to Grant Fidelity for creating a highly affordable piece of equipment that takes the masses into the high end!