Here's the link to most recent review of S&B TVC stage:
http://www.6moons.com/audioreviews/audiozone4/pretone_2.html
http://www.6moons.com/audioreviews/audiozone4/pretone_2.html
Congratulations, Peter 
I have to say that I don't like Mr Ebaen's snobish style... he allways tries the review units in the least recommended scenarios and compares with his beloved tubes gear before squeezing the unit's capabilities.
Some comments:
1) Did you experiment previously with wood base or box? My TVC is wood based but I never experimented with thick aluminium. Maybe this could change the sound.
2) I don't see balanced in/outs. I think this Tx work the best in balanced mode.
3) My TVC sounds better with high output sources or high input sensitivity amps or both. Mainly fuller sound, more dinamics and bass punch. I think users (reviewers) must know that.
Congratuations again for wonderful design.
I don't imagine how anybody could listen to an active pre after listening to a TVC.
(and it matches UCD amp )
Best wishes.
Mauricio
I have to say that I don't like Mr Ebaen's snobish style... he allways tries the review units in the least recommended scenarios and compares with his beloved tubes gear before squeezing the unit's capabilities.
Some comments:
1) Did you experiment previously with wood base or box? My TVC is wood based but I never experimented with thick aluminium. Maybe this could change the sound.
2) I don't see balanced in/outs. I think this Tx work the best in balanced mode.
3) My TVC sounds better with high output sources or high input sensitivity amps or both. Mainly fuller sound, more dinamics and bass punch. I think users (reviewers) must know that.
Congratuations again for wonderful design.
I don't imagine how anybody could listen to an active pre after listening to a TVC.
(and it matches UCD amp
)Best wishes.
Mauricio
Phase switching input
Hey,
I've been toying with switching phase on the input switch of a TVC without tying all the input grounds together.
Below is a sad representation of what I'm trying to do. The mess on the left side represents the input selector rotory switch(no rotory switches on my copy of circuitmaker!!); 3 pole, 4 throw and as represented the three switches would move left/right as one unit(one channel). As connected would allow switching of input phase.
The bottom row of switches just allows the signal negative from the inputs to go to the "ground" part of the preamp regardless of the phase. Is this a good idea??
R1/S1 is just an option to tie the input grounds together in the event that switching inputs causes a "thump" due to different ground potientials of the source units.
The other switches are for Hard/Soft grounding of the inputs and Hard/Float of the output.
Seems to me there would be no problem with this arrangement if the output ground is "floating". But, will there be problems if both input and output are hard grounded?
The funky looking "variable transformer" on the right represents the Tx-102 and the volume control.
Thanks,
Scott
Hey,
I've been toying with switching phase on the input switch of a TVC without tying all the input grounds together.
Below is a sad representation of what I'm trying to do. The mess on the left side represents the input selector rotory switch(no rotory switches on my copy of circuitmaker!!); 3 pole, 4 throw and as represented the three switches would move left/right as one unit(one channel). As connected would allow switching of input phase.
The bottom row of switches just allows the signal negative from the inputs to go to the "ground" part of the preamp regardless of the phase. Is this a good idea??
R1/S1 is just an option to tie the input grounds together in the event that switching inputs causes a "thump" due to different ground potientials of the source units.
The other switches are for Hard/Soft grounding of the inputs and Hard/Float of the output.
Seems to me there would be no problem with this arrangement if the output ground is "floating". But, will there be problems if both input and output are hard grounded?
The funky looking "variable transformer" on the right represents the Tx-102 and the volume control.
Thanks,
Scott
Attachments
anyone understand this
Hi,
I finally got around to building my TVC based on the TX-102 mkiii group buy from almost one year ago. I had one slightly confusing thing happen and wanted to tap into the collective wisdom of the group to see if someone could explain what is happening.
I wired things up in a pretty conventional manner.
I've got 3 inputs switched with a ceramic rotary switch. I wire the primary in standard mode with input to ++, ground to -, and -- wired directly to +.
I'm using a 23 position electroswitch, so I left the 0db tap open and the switch selects between -2db . . . through -52db and referenced to the unlabelled secondary ground (black or white depending on transformer).
I wired the red screen wires from each transformers to input ground.
When first hooked it up, it appeared that the 1st few volume steps were too loud and there wasn't much modulation of volume. One had to go about 6 or 7 clicks before volume started to increase. Measuring the resistance of the output showed that it was approximately 30 ohms and pretty constant until the volume started to rise.
The only thing I could figure out was that the "secondardy ground tap" had a problem so I rewired things using the -52db tap as the secondary ground and things seem to work fine now.
Any thoughts on whats going on?
Thanks,
---Gary
Hi,
I finally got around to building my TVC based on the TX-102 mkiii group buy from almost one year ago. I had one slightly confusing thing happen and wanted to tap into the collective wisdom of the group to see if someone could explain what is happening.
I wired things up in a pretty conventional manner.
I've got 3 inputs switched with a ceramic rotary switch. I wire the primary in standard mode with input to ++, ground to -, and -- wired directly to +.
I'm using a 23 position electroswitch, so I left the 0db tap open and the switch selects between -2db . . . through -52db and referenced to the unlabelled secondary ground (black or white depending on transformer).
I wired the red screen wires from each transformers to input ground.
When first hooked it up, it appeared that the 1st few volume steps were too loud and there wasn't much modulation of volume. One had to go about 6 or 7 clicks before volume started to increase. Measuring the resistance of the output showed that it was approximately 30 ohms and pretty constant until the volume started to rise.
The only thing I could figure out was that the "secondardy ground tap" had a problem so I rewired things using the -52db tap as the secondary ground and things seem to work fine now.
Any thoughts on whats going on?
Thanks,
---Gary
Banned
Joined 2002
Hi all,
I have been using this for a few months now.
My aim was to build by last preamp and so far I feel very pleased with results and no desire for anything else.
I am running my DAC balanced voltage output directly into the pre and my balanced class A amps on the o/p.
No capacitors in signal path except in series with the tweeter - this is seriously transparent
So good news except I just blew up one of the class A's - Oh well I guess I will have to try and build a better one...
I have been using this for a few months now.
My aim was to build by last preamp and so far I feel very pleased with results and no desire for anything else.
I am running my DAC balanced voltage output directly into the pre and my balanced class A amps on the o/p.
No capacitors in signal path except in series with the tweeter - this is seriously transparent
So good news except I just blew up one of the class A's - Oh well I guess I will have to try and build a better one...
Attachments
Banned
Joined 2002
about £300 plus tax
http://www.stevens-billington.co.uk/pagehifi.htm
TX102 Mk3
quite expensive but better that most.
any reports you may hear that the treble is too smooth may be reffering to TX102 mk2. To my ears the treble with the mk3's is excellent ( I have tried both )
mike
http://www.stevens-billington.co.uk/pagehifi.htm
TX102 Mk3
quite expensive but better that most.
any reports you may hear that the treble is too smooth may be reffering to TX102 mk2. To my ears the treble with the mk3's is excellent ( I have tried both )
mike
UCD400 integrated with TX-102s
I just finished this integrated up earlier this Thursday night. It has totally blown me away with how clean it is. After its been running a while if I pause the sources and crank it all the way up I can only just barely hear the hiss. Its easily the quietest system I've heard so far.
Notice that I said after its warmed up. For some reason the right channel makes a gound hum/buzz for about three minutes of music before lapsing into almost total silence. Right now the inputs are hard grounded. I had originally wired up a lift switch, but I thought maybe I was picking up noise from the amp transformer so I pulled it out.
I'd think it was just grounding problems, but the fact it totally goes away has me very confused.
I also am worried I did something dumb when I wired it together. I went ahead and wired both the volume and input selector switches to the TX102s before I wired up the input jacks. I used my meter to tone out the positive and negative because the wire was enameled and braided (2+2) so I couldn't tell them apart. Without thinking I toned out the active selection so I'm worried that my meter could have dumped DC into the transformers. What would the symptoms of a magnetized TX102 be? Could that explain startup humming?
Any other ideas for this mysterious disappearing hum?
Thanks
I just finished this integrated up earlier this Thursday night. It has totally blown me away with how clean it is. After its been running a while if I pause the sources and crank it all the way up I can only just barely hear the hiss. Its easily the quietest system I've heard so far.
Notice that I said after its warmed up. For some reason the right channel makes a gound hum/buzz for about three minutes of music before lapsing into almost total silence. Right now the inputs are hard grounded. I had originally wired up a lift switch, but I thought maybe I was picking up noise from the amp transformer so I pulled it out.
I'd think it was just grounding problems, but the fact it totally goes away has me very confused.
I also am worried I did something dumb when I wired it together. I went ahead and wired both the volume and input selector switches to the TX102s before I wired up the input jacks. I used my meter to tone out the positive and negative because the wire was enameled and braided (2+2) so I couldn't tell them apart. Without thinking I toned out the active selection so I'm worried that my meter could have dumped DC into the transformers. What would the symptoms of a magnetized TX102 be? Could that explain startup humming?
Any other ideas for this mysterious disappearing hum?
Thanks
Ooops my bad, nothing to do with TX102s
I rewired the amp portion when I did the preamp part the other day. When I first got the amp parts I noticed that /ON wire in the hypex molex kk connector was loose. I had carefully pushed it in before and gotten a good connection. Unfortunately this next time I had accidentally pushed it below the connector and it was touching the signal- pin too. /ON is connected to the power supply ground so I was shorting the signal- on the floating balanced signal from the TX102s to the UCD400s. I just fixed the wire connector and its clean now.
Jeremy
I rewired the amp portion when I did the preamp part the other day. When I first got the amp parts I noticed that /ON wire in the hypex molex kk connector was loose. I had carefully pushed it in before and gotten a good connection. Unfortunately this next time I had accidentally pushed it below the connector and it was touching the signal- pin too. /ON is connected to the power supply ground so I was shorting the signal- on the floating balanced signal from the TX102s to the UCD400s. I just fixed the wire connector and its clean now.
Jeremy
Congratulations, samplesj
I'm glad you fixed it!
This is what I want to do in the future ( and save an IC pair )
What source do you use?
I've noticed TVC sounds better (if that can be possible) with high Vout sources. More impact, more fullness.
I'm near complete part collection for my UCD400 monos. Then I will go balanced up to down
Regards.
Mauricio
I'm glad you fixed it!
This is what I want to do in the future ( and save an IC pair
)What source do you use?
I've noticed TVC sounds better (if that can be possible) with high Vout sources. More impact, more fullness.
I'm near complete part collection for my UCD400 monos. Then I will go balanced up to down
Regards.
Mauricio
Mauricio, I've experimented with a several sources, but mostly its been an unmodded Squeezebox2. I'm planning on at least putting in a couple of caps to the outputs and bypassing the opamps, but I've got a couple more projects on the list yet. I also may end up with an external DAC. I just sold my old DAC set and haven't decided where I want to go next.
Unmodded I think the squeezebox2 is pretty hot so your observation may be on the mark. I think I've read stuff about ~6vpp (2.12Vrms).
In my acoustically treated HT room I tried them with a Denon 3910. The 3910 is 2Vrms so they are pretty much the same "hottness". I didn't notice any differences in the fullness, but they are so close. It certainly had good bass impact. I had some pipe organ music going and the floors were rattling pretty good even though the speakers are -3dB at around 40hz.
Aren't most sources around 2Vrms? Are you talking about >2 with more impact/fullness or more of a warning about lower output DACs? If I mod the Squeezebox with a cap I'll drop some output. I wonder if its still a good trade on a TVC?
Jeremy
Unmodded I think the squeezebox2 is pretty hot so your observation may be on the mark. I think I've read stuff about ~6vpp (2.12Vrms).
In my acoustically treated HT room I tried them with a Denon 3910. The 3910 is 2Vrms so they are pretty much the same "hottness". I didn't notice any differences in the fullness, but they are so close. It certainly had good bass impact. I had some pipe organ music going and the floors were rattling pretty good even though the speakers are -3dB at around 40hz.
Aren't most sources around 2Vrms? Are you talking about >2 with more impact/fullness or more of a warning about lower output DACs? If I mod the Squeezebox with a cap I'll drop some output. I wonder if its still a good trade on a TVC?
Jeremy
Hi
Sorry, I don't know squezzebox2
My observation may apply to high output sources, high input sensitivity amps or both. It may have to do with more current with higher attenuation windings: less V out of the TVC is accompanied by more I.
I am not sure about this because my sources are not comparable.
My present DAC is a heavily moded M-Audio superDAC.
See our group here:
http://groups.yahoo.com/group/M-Audio_SuperDAC_2496/
There are many files, schematics of stock unit and proposed mods.
It has "domestic level" output through unbalanced outs (-10dBV nominal; +6dBV peak) and "pro level" output through the balanced outs (+4dBu nominal; +20dBu peak; whatever this could mean...).
It is funny to mod, plenty of space. Mine is sounding very good, fed by a Monarchy Audio DIP upsampler. I suppose when my skills improve I could build a cheaper upsampler circuit
All this was to say that it does sound better through balanced outs (even with bal. to unbal. cable). Unfortunatelly, the unbalanced opamps are "summing opamps" for the balanced ones, which means one step more and degradation of sound
The pros of high (balanced) Vout are, IMHO, probably, more fulness and better noise rejection (V noise v/s V signal ?) specially with the balanced input of UCD's.
The cons are risk of too much volume with high sensitivity amps (not with UCD), and ... I can't think of any other.
If you use ONLY the TVC as preamp I believe the coupling caps are not needed (?) If you bypass the opamps I think you will have lower Vout and risk of poorer bass/leaner sound, IF my hypothesis is correct.
Well, I'm only an amateur and could be totally wrong
Good luck with your projects
Mauricio
Sorry, I don't know squezzebox2
My observation may apply to high output sources, high input sensitivity amps or both. It may have to do with more current with higher attenuation windings: less V out of the TVC is accompanied by more I.
I am not sure about this because my sources are not comparable.
My present DAC is a heavily moded M-Audio superDAC.
See our group here:
http://groups.yahoo.com/group/M-Audio_SuperDAC_2496/
There are many files, schematics of stock unit and proposed mods.
It has "domestic level" output through unbalanced outs (-10dBV nominal; +6dBV peak) and "pro level" output through the balanced outs (+4dBu nominal; +20dBu peak; whatever this could mean...).
It is funny to mod, plenty of space. Mine is sounding very good, fed by a Monarchy Audio DIP upsampler. I suppose when my skills improve I could build a cheaper upsampler circuit
All this was to say that it does sound better through balanced outs (even with bal. to unbal. cable). Unfortunatelly, the unbalanced opamps are "summing opamps" for the balanced ones, which means one step more and degradation of sound
The pros of high (balanced) Vout are, IMHO, probably, more fulness and better noise rejection (V noise v/s V signal ?) specially with the balanced input of UCD's.
The cons are risk of too much volume with high sensitivity amps (not with UCD), and ... I can't think of any other.
If you use ONLY the TVC as preamp I believe the coupling caps are not needed (?) If you bypass the opamps I think you will have lower Vout and risk of poorer bass/leaner sound, IF my hypothesis is correct.
Well, I'm only an amateur and could be totally wrong
Good luck with your projects
Mauricio
Help a Novice
Hello,
I am a novice.
Already have the S&B Tx + Selden rotary switch and parts.
Will only use only a RCA In / Out Configuration
Now I am a bit foxed by the Selden Rotary Switch, It came with no schematics and I am figuring the Hot switch will be as marked and the Ground should be the '0' switch, However which is the zero(mute) switch?
Kindly check my jpeg and help me confirm if the Hot is as overmarked, adn which is the Mute point.
TashiDelek
Tops
Hello,
I am a novice.
Already have the S&B Tx + Selden rotary switch and parts.
Will only use only a RCA In / Out Configuration
Now I am a bit foxed by the Selden Rotary Switch, It came with no schematics and I am figuring the Hot switch will be as marked and the Ground should be the '0' switch, However which is the zero(mute) switch?
Kindly check my jpeg and help me confirm if the Hot is as overmarked, adn which is the Mute point.
TashiDelek
Tops
Hi all, I bought a pair of 102's recently and have had them rigged up on the test bench sounding pretty good. I decided to wire it all up yesterday like so.
Transformer + and -- together
RCA input Hot to ++ of transformer
RCA Ground to - of transformer
numbered outs of transformer to 24 way switch
Output pin of switch to pin 2 of XLR
xlr pin 1 to ground
pink wire from transformers to ground
black/white wires from transformer (unlabled) to ground.
This produced hum so I grounded the RCA cold to the same ground point.
Now the issue is that it appears to be in mono, disconnecting one chanel at the input still plays through both amps. The only place I can see the two channles being connected is at earth, is this where my problem lies you think?
Should I try a seperate earth? Have I made an obvious error?
Thanks
Transformer + and -- together
RCA input Hot to ++ of transformer
RCA Ground to - of transformer
numbered outs of transformer to 24 way switch
Output pin of switch to pin 2 of XLR
xlr pin 1 to ground
pink wire from transformers to ground
black/white wires from transformer (unlabled) to ground.
This produced hum so I grounded the RCA cold to the same ground point.
Now the issue is that it appears to be in mono, disconnecting one chanel at the input still plays through both amps. The only place I can see the two channles being connected is at earth, is this where my problem lies you think?
Should I try a seperate earth? Have I made an obvious error?
Thanks