Triode Lab 2A3M-II RS GT. The bass sounds of great quality, but I cannot confirm the extension and energy down below
SET amp owners thread
- Thread starter bonzo75
- Start date
I've provided tips for optimizing SET performance; as well if you don't understand the weaknesses of the technology you won't get the most out of it.
I have my 845 Audion in. Full Mark II Build. If I did not have the Blade to know better, I would be very impressed. Having the Blade I hear the wool. Loss of resolution. Lack of upper extension. A pleasant body and midrange. Nice weight. But really, nothing very Natural Sound. I can hear what Audion is aiming for. Its better than the real Line Magnetic, not the fake ones. I have had one of them bere. The Line Magnetic was a lot noisier and more trebly, but not in a good way. These are pretty smooth and liquid. Nothing wrong with what I have. Probably a decent representation of the tube and what you get from a $15k SET 845.
It may be better on a hogher efficiency speaker with smaller drivers. Its pretty quiet. Not dead quiet. But good enough. Especially with the Elrog 845 and the Ifi 6922 variant as the coupling cap.
Per my post below, if I biamped the speaker and put the 845 to just the 10" coax, the 845 would probably play with more air and space. Less wool. I doubt it would speed up much. My reference is incredible fast and clean.
Biamping would be crossing the coax around 250htz to 450htz. That's roughly where it is now. The 15".drivers do a lot of work.
Very Directional above 300hz , 500 would be the max upper limit for good fidelity IMO , not to mention cone mass ..
Been letting the amp play. As you get use to it, its very pleasant and easy to listen too. Take off the audiophile hat and it becomes a enjoyable amp. BUT. Stupid volume on the front pops sometimes. It has a stepped volume attenuator. I think the signal goes through it, then into the signal tube. Well, I changed the pre tube to a very nice Telefunken E88CC that cost about $350 per tube. Stupid amp may have popped a couple times it popped really loud, Now the tube is microphonic. I'm pissed. I;m wondering if there is any way to get into the attenuator and spray deox or something to stop it, I don't want to risk any other tubes.
You might want to put this in your thread of 'I'm tired of failing amps'...
But the nice Telefunken was likely already microphonic. There's no circuit defect that can cause a tube to become microphonic! I'd return that Telefunken if you can.
A stepped attenuator can make a popping sound when you adjust it if there is even a slight Voltage on the control. That could come from a tube defect and it could come from the source at the input of the amp. Disconnect the source and see if the pop is still there. If the pop only occurs at certain positions of the control, its a bad control.
I've found pops and scratch on attenuators can come from leaky capacitors upstream which allow DC to be on the contacts.
Yes, better place on the failing amp thread.
Thanks for the education that it is not the pop that fried the tube. Maybe it was bad. It was never and issue in the past. But who know what happens as tubes sit over the years.
It pop with a couple different sources. And it may happen at a odd spot here and there. And it gets better as it is used. The more I use it, the less it pops. I suspect its dirty inside. I am going to open the top and see if I can get inside the attenuator to spray it. If I can, should I use Deoxit or should I use some sort of special contact cleaner.
I get the SET attraction. The more you use it and forget about other amps in the arsenal, the more you like it. You have to take off the analytical hat and enjoy it for what it is. Its not as fast and clean as my other amp. But it warm and organic. I don't find I want to play if very loud. I'm am probably in the 62db area. But its relaxing and enjoyable to play music and forget at that level.
hmm. This amp was totally rebuild about a year ago. Then it sat in a box for a year. I took it out and it popped with every turn of the volume. Now it is very intermittent and usually at louder volumes. Places where I have not been turning the volume too. I think its dirty. Sat too long and maybe built up some oxidation. Its been in a case in my house in a conditioned space. Not sure why it would happen. I sort of doubt anything is leaking. I will look around.
It might not be dirt as much as oxidation or contamination from the air (or god forbid, smoking) on the contacts. DeOxit will cure those but go easy on it. The best way to clean contacts like that is to apply with a Q tip and lightly scrub the contacts (if that is possible of course) rather than squirting it in the control. In the old days when contacts were manly type things, technicians used pencil erasers to clean the large contacts.
I used pencil erasers on my HO train tracks. I can not get inside the POT. See the Sick of Failing Amplifiers thread. I just posted pictures of the POT. I
Then you'll need to go the squirt route. Just work the control well for a couple minutes after applying the cleaner. Also be very careful that you don't dissolve any lubrication on the shaft while squirting cleaner inside. Doing so can not only deposit that lubricant on the contacts, but it can affect the turning feel of the pot.
Before you do anything though, it would be worthwhile to measure the pins on the pot for any DC voltage. If there's DC on the pot, then no amount of cleaning will get rid of the transients.
Have you signal sources that dc coupled?e.g dac
You often see these days that there are no coupling capacitors in front of the volume pot on tube amps. That's high-end today, unfortunately DC voltage destroys contacts and sliding tracks over a longer period.
If there isn't one, just solder 0.1-0.15uf into the signal path. Just try it out and see if there is no more noise when switching. A photo of this would be helpful.
Do it the old school standard.
microphonics, simply tap the tube gently with a pen. If noises occur, replacing the tube is the only solution. The noises usually come from the tube grid, which has become mechanically loose in the tube.
You often see these days that there are no coupling capacitors in front of the volume pot on tube amps. That's high-end today, unfortunately DC voltage destroys contacts and sliding tracks over a longer period.
If there isn't one, just solder 0.1-0.15uf into the signal path. Just try it out and see if there is no more noise when switching. A photo of this would be helpful.
Do it the old school standard.
microphonics, simply tap the tube gently with a pen. If noises occur, replacing the tube is the only solution. The noises usually come from the tube grid, which has become mechanically loose in the tube.
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I am sick of failing amplifiers
I had Mcinsosh issues too. At the beginning of my journey I bought a Mcintosh preamp. When you turned the volume knob, the right channel would rise 3 clicks and get louder but the left would not change. On the 4th click, the left would jump up to match the right. I sent it back 3 times. It...
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Here are the pictures.
Use the Deoxit F5 spray in the green and black and white can. Its the one that leaves a bit of lubricating non-conductive residue. This prevents the contacts being damaged. Any attenuator like this comes with a bit of contact lubricant. Straight on contact cleaner will remove the lubricant and the control will fail in short order.
Use the least bit of spray you can and do as @Ampexed advised.
Film caps rarely get leaky unless they are ancient. I run into that sort of thing when I refurbish stuff from the 1950s or earlier. But that shouldn't be happening with any modern stuff. From all this it just sounds like this amp has been sitting around unused too long.
I really don't like that schematic! That 150V can't be right.
That is not my schematic. It was an example from DasguteOhr
I referring mostly to electrolytics, especially old ones.
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