[OctavianH]

12E1 and gyrator effect make the bias measure swing a little until the tube is hot (15 minutes) at least for the one I have...

I have here 3 types of 12E1 and while 2 act as you say there is one exception, the GEC 12E1. This one behaves perfectly normal. Others (Ediswan and STC) act crazy at startup. I cannot say why, I just say what I have observed.

 

[Isaacc7]

Finally back to a loved combo on the Odyssey, ktz41 on the input and GU50 on the output. Going to soak this in for a while before getting back to experimenting with tubes. It’s good to have it back!

 

[Isaacc7]

Mind you I had some drama getting this working. Put in the output tubes and turned the b+ and bias all the way down. Turned on amp. POP! From the right side. Hmm… Huh, weird, the b+ is starting at 300v instead of 250v. Left tubes bias up fine. Right side? Bias meter dead. Oh wait, one of the tubes isn’t lit up. Turn off amp, pull tube, reseat adapter and put it back in. Now it lights up but bias meter is still dead. Check fuse, yup, blown fuse. Replace fuse and now everything is working fine including the voltage starting at 250v.

Ah, the joys of tube amps lol.

 

[triod750]

You get what you need and then some. Fuses can be a blessing.

My DAC was dead last week. Suspected amp first. Opened DAC and checked the fuse. It looked ok but I changed it anyway. Music back.

 

[OctavianH]

I was reading a little bit about EL300 and got on this link. Interesting stuff.

In the meantime I also bought a few tubes, in range of 5-10EUR/piece. Nothing famous, but with good potential to surpass many famous ones.

PS: It seems these guys with the Lampizator roll much more interesting tubes than our fellow headphone amplifier users. 4654, OS1, P17C. Good ones. Here also some info.

 

[Designsfx]

I was reading a little bit about EL300 and got on this link. Interesting stuff.

In the meantime I also bought a few tubes, in range of 5-10EUR/piece. Nothing famous, but with good potential to surpass many famous ones.

PS: It seems these guys with the Lampizator roll much more interesting tubes than our fellow headphone amplifier users. 4654, OS1, P17C. Good ones. Here also some info.

“Those” Lampizator guys have come full circle now that they have a new dac that uses pentodes. The TRP started the pentode chase but many jumped to DHT when upgrading to the Golden Gate/Pacific dacs. Lots of expensive/un-obtanium tubes listed from large collections over there!

 

[OctavianH]

“Those” Lampizator guys have come full circle now that they have a new dac that uses pentodes. The TRP started the pentode chase but many jumped to DHT when upgrading to the Golden Gate/Pacific dacs. Lots of expensive/un-obtanium tubes listed from large collections over there!

Yes. Do you know by chance what plate voltage and currents they have on those DACs? (not necessarily Horizon which I think it's the most expensive, but one which can use such pentodes). In my view such a DAC makes sense connected to a power amplifier for a speaker setup. I would not use something like this connected to a tube amplifier for headphones. Of course, I might be wrong.

 

[hpamdr]

Yes. Do you know by chance what plate voltage and currents they have on those DACs? (not necessarily Horizon which I think it's the most expensive, but one which can use such pentodes). In my view such a DAC makes sense connected to a power amplifier for a speaker setup. I would not use something like this connected to a tube amplifier for headphones. Of course, I might be wrong.

Those Dac are not power amplifier, so all the used tube are only to provide small power in fact too much that have to be dissipated. You can give a look here http://www.lampizator.eu/lampizator/Measurements/lampizator measurements.html but who is really listening Sine, Square at 400Hz ???

// I would say that it is for me a non sens to use such cavalry in a DAC. You can alter the signal in next devices ( pre-amplifier, amplifier)...

If you like Tubes in dac you can also give a look here https://www.totaldac.com/D1-tube-eng.htm

 

[Designsfx]

Yes. Do you know by chance what plate voltage and currents they have on those DACs? (not necessarily Horizon which I think it's the most expensive, but one which can use such pentodes). In my view such a DAC makes sense connected to a power amplifier for a speaker setup. I would not use something like this connected to a tube amplifier for headphones. Of course, I might be wrong.

I don’t have a full understanding of how these parameters play across the product line as each model uses a different configuration of tubes. I know from the documentation of the model I own (Golden Atlantic TRP3 balanced) that the power tube sockets would measure at 240 VDC without a tube but this is reduced during operation with tubes in place. The dac operates in single ended triode mode/anode follower so that voltage is dropped by the number of tubes in use. I was told the max ampacity of each power tube socket should not exceed 2 amps and all power tubes are auto biased as well. Each power tube socket (2 for S/E dacs, 4 for balanced) powers the +/- phase of the channel output so a balanced dac can be run single ended if preferred.

You could use this Dac in your headphone amp if the model were equipped with volume control. Many people run their two channel speaker systems this way as well. I ordered mine without volume control as I already own an excellent preamp.

I know with my dac I have found better performance with the use of indirectly heated triodes as opposed to pentodes. While I did not chase uber expensive pentodes I did use fairly high output 6L6 quads and found the 6J5 (and even 6SN7) family to provide better sound and higher output.

I’m attaching a small section of the manual they provide that covers tube rolling in the TRP.

 

[hpamdr]

6L6 strapped as triode is a good compromise but if you like cleaner sound a quad of 6J5 is less powerful but is very linear from 40 to 200V Anode voltage... 6SN7 is a dual 6j5 so having 4 is like having 8 triodes -> bigger amplification factor if you strap 6sn7 as // triode.
I'm not very familiar with Lampizator output stage but it makes sense with volume pot and a big SS amp in order to not use any pre-amplifier. Adding tubes to all stages is for me too complicated to setup and tricky to have a kind of objective analysis of what i feel.

 

[Designsfx]

6L6 strapped as triode is a good compromise but if you like cleaner sound a quad of 6J5 is less powerful but is very linear from 40 to 200V Anode voltage... 6SN7 is a dual 6j5 so having 4 is like having 8 triodes -> bigger amplification factor if you strap 6sn7 as // triode.
I'm not very familiar with Lampizator output stage but it makes sense with volume pot and a big SS amp in order to not use any pre-amplifier. Adding tubes to all stages is for me too complicated to setup and tricky to have a kind of objective analysis of what i feel.

So far I’m kinda on the fence between the 6J5 (quad) and the 6SN7 (quad) in this Dac. Maybe because I only have one set of 6SN7’s to compare to. The set I have are early 50’s Ken Rads and they dig pretty deep on some tracks but the 6J5’s are more consistent overall (at least in my system). Granted- as you eluded to there may be some synergy there between my preamp and amplifier which combined are using a fair amount of tubes. I’m sure I’ll get into the details/differences of the two more as time passes and I collect more of them. One tube that has really excelled in this Dac is the Soviet 6c5c- a different take on the 6J5.
As I reallize this is the Uttra Sonic Studio’s thread I’ll let you guys get back to the subject at hand!

 

[Isaacc7]

My tube rolling journey continues!

The first new tubes I wanted to try were the Svetlana 6j7. These are metal tubes. Turned on the amp and the left side is pretty low. Turn off the amp, reset the tubes in the adapter, turn it back on. Still low. Sounds like one of the tubes isn't working. The metal tubes stay hot for too long for me to fiddle with them immediately. Put the offending pair off to the side and it's on to the next tube.

The CV4062 and adapters happened to be right next to me. I'm going to keep the GU50 output tubes for now so these will be put into the 2x triode 6v6 adapters for input duties. Not super impressive at the beginning but I let them play through most of the day. They have opened up quite a bit now. The bass is really incredible. Not just loud but deep and controlled. There is also a presence to the music that stands out. How much that has to do with a weird coloration in the upper mid I don't know. It gives steel strings and slightly higher piano notes a bit of unpleasant glare. I might try some different tubes in the preamp if it persists.

The bass is really something though. I don't know if this is because of these particular tubes or because this is the first time I am using one that was designed as an output tube as an input. Maybe they are just capable of delivering more to the output tubes? I anticipate using these for several more nights at least. Think the next tube will be the KT81, a tube I have been dying to use for quite a while.

 

[hpamdr]

Soviet 6c5c- a different take on the 6J5.

The very old refektor 6c5c are exquisite tube (GoodForTheBucks) I have a pair sitting in my Euphoria with GEC 6080.
In place of 6L6 in your DAC, you should give a try to 6M6 tubes (if you can find them) it is a direct replacement of EL3N / EL11 with EL34, 6L6 pinout. This is not the most linear tube but like EL3N you have sensation of tighter bass and a wider acoustic scene... The next question, is how it match with your pre-amp / amp /...

 

[Isaacc7]

Couldn't take the glare anymore. Once I heard it I couldn't ignore it. Swapped out the 14n7 in the preamp for Raytheon 12j5wgt. That has smoothed out the response nicely but I've lost the crazy bass. I need to listen for a while to see if it's just normal or actually missing something.

I also noticed that the cv4062 have significantly less gain than the typical 6sn7 tube. My preamp volume is at about 1:30 instead of closer to 10:30. Luckily I have lots of drive available with this preamp. My passive would not cut it with these inputs.

 

[hpamdr]

I also noticed that the cv4062 have significantly less gain than the typical 6sn7 tube.

Amp factor of cv4062 is 10 in single triode mode, this is half of single triode of 6SN7 (20). If you strap 6SN7 to have 2 triode in // the amp factor remain the same but Internal resistance is halved and noise is halved. One 6SN7 tube for a balanced chanel..