Welcome, Guest. Please Login or Register
Decware Audio Forums
11/27/14 at 12:02:12


Pages: 1 ... 15 16 17 18 19 ... 27
Send Topic Print
Mini Torii SE Amplifier (Read 77275 times)
Lon
Seasoned Member
****


"Love without
guts is
worthless!"
Philip K. D*ck

Posts: 7818
Re: Mini Torii SE Amplifier
Reply #240 - 04/14/12 at 02:12:40
 
What? You call that music? Smiley Just kidding. Glad you're listening to music.
Back to top
 
 

Decware:ERR,HR-1,ZP3,CSP2+,Torii Mk III,PS Audio PWT+DS,PowerBases,PPP,AC-12 pcs, Denon DVD-A1UDCI, Rega RP3 +TTPSU,white belt+Exact2, VooDoo Cable:Stradivarius, Ultra Linear+Evo ICs, Iso-Pods,Mapleshade:Double Heiix Plus,Samsonv2+v3 +4" platforms,Herbie's Iso-Cup
  IP Logged
Raduschka
Seasoned Member
****




Posts: 210
Re: Mini Torii SE Amplifier
Reply #241 - 04/14/12 at 02:30:11
 
haha,

is that an inexact category again? Smiley
Back to top
 
 
  IP Logged
Fireblade
Seasoned Member
****


Knowledge comes, but
wisdom lingers.
A.L.Tennyson

Posts: 707
Re: Mini Torii SE Amplifier
Reply #242 - 04/14/12 at 03:08:18
 
Radu,

Lowering the DAC's output voltage will help you attain a lower volume at that 2nd click, but it does not necessarilly have any effect upon dynamics, IMHO.

The idea behind 'riding the gain' to improve overall dynamics, is to accumulate unreleased gain potential on the input side, so as to be able to release a fraction of it through your amp's volume controls (output side of the equation).  With the ZStage in place, you achieve the desired end volume control, plus the dynamics effect.

It also works the other way around: If the music source is heavy and congested, lean up the input side and increase the conditional volume (end volume is the compounded effect of both input and output controls) on your amp, for a leaner, more transparent sound.  This, also attainable at the desired optimum end volume setting.

One thing is to correct the hyper sensitivity of your amp's volume control (just reducing the DAC's output voltage), another, more synergistic approach, is to achieve the same results but with added, more lively dynamics.

I may be wrong, but this is how I see it.   Great drawings, BTW!
Back to top
 
 

Laptop-Foobar2K-ASIO Direct//WD 2.0Tb HDD//Audio Gd USB cable//Audio Gd NFB 3 (2014) DAC//Decware Silver Ref IC's//Decware Mini Torii SE//Kimber Kable spkr cbls//Decware DM945's//Velodyne DLS 3500//BJC SUB Cbls//Tripp Lite 500 Isolation Trnsf.//Jellyfish Pwr Cord
  IP Logged
Raduschka
Seasoned Member
****




Posts: 210
Re: Mini Torii SE Amplifier
Reply #243 - 04/14/12 at 03:17:32
 
A tube gain stage should be easy to make.... I just need to find a schematic.
But won't it add a layer of circuitry between the source and the amp? A new pair of pots, etc...
I just got a pair of pretty expensive atts!
Won't it blur the details in exchange of better dynamics? I never used a preamp, so please forgive the amateurism.
Back to top
 
 
  IP Logged
Raduschka
Seasoned Member
****




Posts: 210
Re: Mini Torii SE Amplifier
Reply #244 - 04/14/12 at 03:21:54
 
oh wait, I got it! If I make a tube gain stage I can take out the attenuators from the MT and use it as a power amp? Is that the idea?
Back to top
 
 
  IP Logged
Fireblade
Seasoned Member
****


Knowledge comes, but
wisdom lingers.
A.L.Tennyson

Posts: 707
Re: Mini Torii SE Amplifier
Reply #245 - 04/14/12 at 03:42:07
 
Yes to your first question, no to the second.  Indeed, with the ZStage there's another component and a pair of added cables involved, which, from a purist viewpoint, is not ideal.  But in return, you get boosted dynamics.  Decware's components are really transparent, so the ZStage should not pose much in terms of degradation relative to more common preamps.

You already ordered the attenuators and I would suggest (if you want the added benefits of increased dynamics), to replace the current volume pots on the M-T with them.  Then, you can plug in a ZStage (or CSP2+ if you need more inputs) in the signal path between the DAC and the M-T and get the best overall results.  Make sure to use short, good quality IC's.

If you can build your own ZStage-like version, that's even better, except make sure it ends up being really transparent, otherwise you run the risk of adding non-insignificant sonic degradation.

In the end, the attenuators can be useful at pinpointing the exact volume you want (both day and night sessions), and the ZStage will improve upon sound dynamics.  Best of both worlds, on top of already having installed those great VCaps.   Wink







Back to top
 
 

Laptop-Foobar2K-ASIO Direct//WD 2.0Tb HDD//Audio Gd USB cable//Audio Gd NFB 3 (2014) DAC//Decware Silver Ref IC's//Decware Mini Torii SE//Kimber Kable spkr cbls//Decware DM945's//Velodyne DLS 3500//BJC SUB Cbls//Tripp Lite 500 Isolation Trnsf.//Jellyfish Pwr Cord
  IP Logged
Raduschka
Seasoned Member
****




Posts: 210
Re: Mini Torii SE Amplifier
Reply #246 - 04/14/12 at 03:45:18
 
I love your optimism Fireblade! All I need now is a schematic and I could start gathering the parts.
Back to top
 
 
  IP Logged
Raduschka
Seasoned Member
****




Posts: 210
Re: Mini Torii SE Amplifier
Reply #247 - 04/14/12 at 04:33:28
 
this is the analog output board of my DIY audionote dac (6922 tubes)I rewired the original pcb in point-to-point on a piece of crap-wood from the 1$ store Smiley
If I made the output of this dac variable, would that equate to a zstage? Or rather a zbox, because I couldn't push it higher than its maximum 2.5V. Is it necessary to go up to 5v in order to be able to 'ride the gain' on the MT?

audionote dac2.1 ptp par raduschkamuschka, sur Flickr
Back to top
 
 
  IP Logged
Raduschka
Seasoned Member
****




Posts: 210
Re: Mini Torii SE Amplifier
Reply #248 - 04/14/12 at 04:35:44
 
Back to top
 
 
  IP Logged
Raduschka
Seasoned Member
****




Posts: 210
Re: Mini Torii SE Amplifier
Reply #249 - 04/14/12 at 07:24:38
 
I am about to build a zstage, based on the kit4 schematic provided by Steve on the website. i assume this is the same concept as the finished product, minus the frontal switch and the 0c2 rectifier. I ordered parts from partsconnexion and I happen to have a lot of useful parts, including a great transformer that came with the zkit1. I have the auricaps he uses in the zstage, one stereo alps pot lying around, one great 6922, etc. I just do not understand where the solid core copper wire goes from the input rca's. It goes straight to the tube alright, but what does it do there? Shouldn't it rather go to the volume pot ground?
Back to top
 
 
  IP Logged
erik2a3
Senior Member
***




Posts: 95
Re: Mini Torii SE Amplifier
Reply #250 - 04/14/12 at 12:22:43
 
Lon: I surely mean ZBox for the very reason that is simply an interstage impedance buffer.  Gain is the last thing that is needed in this case.  However, the input  voltage to it can be attenuated, which is precisely why it is particularly well suited here.  The output impededence spec. satisfactory, but not really low, which wouls be better, and have the additional capability of being able to drive the increased capacitance associates with longer ICs.
Back to top
 
 

Have fun!
erik
  IP Logged
erik2a3
Senior Member
***




Posts: 95
Re: Mini Torii SE Amplifier
Reply #251 - 04/14/12 at 12:25:51
 
So, your about to build a preamp!  ;) do enjoy the process!
Back to top
 
 

Have fun!
erik
  IP Logged
Lon
Seasoned Member
****


"Love without
guts is
worthless!"
Philip K. D*ck

Posts: 7818
Re: Mini Torii SE Amplifier
Reply #252 - 04/14/12 at 13:33:27
 
Okay, sorry.
Back to top
 
 

Decware:ERR,HR-1,ZP3,CSP2+,Torii Mk III,PS Audio PWT+DS,PowerBases,PPP,AC-12 pcs, Denon DVD-A1UDCI, Rega RP3 +TTPSU,white belt+Exact2, VooDoo Cable:Stradivarius, Ultra Linear+Evo ICs, Iso-Pods,Mapleshade:Double Heiix Plus,Samsonv2+v3 +4" platforms,Herbie's Iso-Cup
  IP Logged
Fireblade
Seasoned Member
****


Knowledge comes, but
wisdom lingers.
A.L.Tennyson

Posts: 707
Re: Mini Torii SE Amplifier
Reply #253 - 04/14/12 at 14:02:30
 
I guess theZBox will work too, absolutely:  The source is 2.5 V and the amp may go full power at 2 Volts or less, depending on the driver tube (1 Volt with the 12aT7).  In any case, there's a positive output voltage differential between the ZBox and amp, enough to boost dynamics riding the gain through the ZBox output control.  

In this case, the volume settings between the two components would be adjusted so that there's a positive voltage (gain) differential between the ZBox output and the amp's output.  In the case of a 12aT7 driver, this difference is a little less than 1.5 V and significantly less with the 12aU7 driver, although probably still enough.

Same principle, only in this case the extra gain of the ZStage (up to 5 Volts) is not required due to the excessive source output voltage and the amp's highish gain.  A simple passive preamp would work the same way, as would an output-controlled DAC.

Those brand new attenuators will play a role in better dialing-in (fine-tune) that volume level on the amp to precisely allow listenable volumes and at the same time improving the dynamics through the ZBox output control.  
Back to top
 
« Last Edit: 04/14/12 at 14:11:22 by Fireblade »  

Laptop-Foobar2K-ASIO Direct//WD 2.0Tb HDD//Audio Gd USB cable//Audio Gd NFB 3 (2014) DAC//Decware Silver Ref IC's//Decware Mini Torii SE//Kimber Kable spkr cbls//Decware DM945's//Velodyne DLS 3500//BJC SUB Cbls//Tripp Lite 500 Isolation Trnsf.//Jellyfish Pwr Cord
  IP Logged
Raduschka
Seasoned Member
****




Posts: 210
Re: Mini Torii SE Amplifier
Reply #254 - 04/14/12 at 14:08:38
 
good morning Sirs,

Brian of AudioNote casually wrote that the output of my DAC is rated at 2V. The specs say 2.5V. Right now I have lowered that considerably by lowering the value of some resistors on the digital board. Don't ask me which.
I just woke up, but soon I am going to measure the output voltage of that thing with a 1khz signal.
I am a little confused now, isn't a passive preamp just a set of good quality volume pots btw the dac and the MT?
Back to top
 
 
  IP Logged
Pages: 1 ... 15 16 17 18 19 ... 27
Send Topic Print