Thinking about going tubes

tonyb wrote: »

Try a tubed Pre with the SS amp you have now. No need to buy 2 pieces off the bat.

I think you should have said, you need to buy 2 pieces that are BAT. (see above post).

stangman67 wrote: »

mhardy6647 wrote: »

DSC_0132 by Mark Hardy, on Flickr

This picture makes me want to go tubes all the more. The cool factor is just out of this world

Well, that was (of course) my intent; my work is done here

This being said - the amp and preamp shown would not be a good match for your loudspeakers. It's a single-ended 2A3 amplifier (3.5 watts per channel) with no negative feedback.

I don't know much about this particular amplifier (the Rogue) but, by and large, the vacuum tube amplifiers are phenomenally simple devices -- easy to troubleshoot & repair (and very forgiving of things like power surges). As long as the transformers are all OK, there's not much to be afraid of in terms of buying an iffy amplifier.

Now, this isn't to say that any needed repairs will be inexpensive -- but they should be straightforward.

As to tubes, yes, there are many ills (some pretty serious) that can be caused by tired or bad tubes. This said, even modern production vacuum tubes are pretty robust little gizmos (despite anti-tube marketing used in the 1960s to sell the consumer the benefits of glorious transistor sound). The output tubes can certainly get tired -- especially if a given amp runs them "hard" (near, or past, their specified operating limits). And tired/bad output tubes can have a multitude of effects, from audible degradation to damage of other components. But they're also easy to change (if not necessarily cheap)!

The small signal tubes (phase splitters, preamp tubes, and voltage amp/driver tubes) - again, given prudent circuit design - can and should last for thousands (even 10s of thousands of hours).

Especially for small signal tubes, if an amplifier has, e.g., one weak channel, or noise in one channel, an easy & valuable troubleshooting tool is to simply swap tubes between channels, and see if the "trouble" follows a tube,

This approach can also work for power amp tubes, but in some amplifier circuits, rebiasing may be required. I don't know what bias scheme the Rogue amps use, sorry.

I hope this soliloquy is reassuring and not just incomprehensible

Good luck!

EDIT: Oh, two things about testing "unknown" tube amplifiers.
1) Always connect a load to the outputs -- either test speakers or dummy loads (8 ohm power resistors, ideally noninductive ones). Transformer-coupled amplifiers don't like open circuits, and output transformers tend to be expensive.

2) Be on the lookout for red plating output tubes. A number of pathological conditions can result in one (or more) output tubes dissipating way more power than they're meant to. In such a case, the tube's plate structure can get red hot. This is a sign of pretty severe trauma; don't operate an amplifier with a red plating tube (or tubes)!
The problem could just be a tired tube that cannot hold bias, or a bad coupling capacitor, or issues with the bias supply circuit (or the bias level, if adjustable) -- but it's bad, bad, bad.

Geez Doc, the poor lad just wants to go look at a Rogue.

tonyb wrote: »

Geez Doc, the poor lad just wants to go look at a Rogue.

Hey, I was trying to encourage him!

And I was gettin' caffeinated for the day...

a cheap Chinese generic brand 2A3
DSC_0002 by icouldbeahero, on Flickr

Decware Zen SE-84B (single-ended EL84 stereo amp)
DSC_9988 by icouldbeahero, on Flickr

The back office of a McIntosh MR-67 tuner
DSC_0255 by Mark Hardy, on Flickr

The first two photos were taken by our son:
http://icouldbeahero.blogspot.com

stangman67 wrote: »

I'm getting real jealous over here.

Mission accomplished.

I'm going to listen to a few integrated amps over the weekend from Primaluna and LM. Kevin from upscale audio says the Focal and Primaluna combo is magical and he seems to be someone with a wealth of knowledge.

Sounds good!

Next stop:

direct coupled.
sweet.

You can always check out your local Craig's List. Just saw this in San Antonio $500 with extra tubes.

https://sanantonio.craigslist.org/ele/d/yaqin-mc-13s-tube-amplifier/6450075562.html

If you really want to torture yourself, go to Deja Vu Audio in McLean, VA

stangman67 wrote: »

Got my ears on a few amps today. I went down to Command Performance AV in the DC area. The guys there were awesome and they had a lot of cool stuff. I went because I saw they were a line magnetic dealer, but they didn't have anything in stock. They were also rogue and primaluna dealers which I was not expecting.

They had a set of Focal 926's setup in a room and I was able to listen to the Primaluna Prologue Premium which was initially one of the three integrated amps I was considering. I was initially very impressed, seemed like it matched perfectly with the Focals as I had heard (read: no brightness to speak of). I liked the tonal quality and the imaging/soundstage was impressive. I very much enjoyed the hour or so I listened to this combo. The big drawback and in the end the reason I will not be getting this amp is the lacking bass. I was obviously expecting this vice when I heard the focals with 300 watts on tap but it was a bigger difference than I was prepared for.

I then made the mistake of listening to the Primaluna Dialogue HP which has 80 watts per channel (and a 4500 price tag ). All the qualities of the prologue that I liked were still present with much more defined and ample bass. I only listened to a few songs as this amp is well outside of my price range and I didn't want to be tempted to do something stupid.

So with this I now know that a 30ish WPC tube amp probably won't be able to satisfy my listening tastes. So I am keeping my TEAC for the time being and will be mulling over Tube Pre/SS amp or maybe saving for something like the Dialogue HP. I really want to find a combo I will love for a long time. That may still be the Teac, just need to give it a chance with the Focals, or I may give Mike's SLP-03 a shot when he is ready to let it go

Said this early on....ss amp, tube pre. You get the bass slam of the SS muscle and the tone and air of the tubes. Makes for an enjoyable experience with any genre of music.

Look for a Joule would be my suggestion. Cary is nice also, depending on the model. My opinion though, is for the price Joule's go for on the used markets, you'd be hard pressed to do better. Down the line, add a Butler amp and I can't imagine anyone not liking that combination.