Listening Session

Over the weekend, I had time to listen for a few hours for comparisons / contrasts between Triode/Pentode with various input sources. Equipment used:
VTA ST-70 with KT66's
Parasound HaloP5 preamp
Oppo 105 BDP
Rega Planar 3. Ortofon quintet bronze MC
Paradigm Studio 10 V5
While listening, I was reading various reviews of Triode versus Pentode. Most all suggest Triode for soundstage / imaging. I really prefer Pentode with the Paradigm speakers. Granted these are small discontinued bookshelf speakers and not my main listening speakers but I was absolutely thrilled with how the system sounded. Back and forth between BDP and Vinyl and playing the same tracks in both P and T modes, I heard better imaging within the soundstage. I was careful not to have the increased volume fool me, had to reduce it about 15% when comparing but Pentode to me, was the winner. Nora Jones vinyl, Diana Krall SACD, Eagles live in both formats, The Crusaders vinyl, Rob Wassermann Duets vinyl. I could really hear microphone placements much better in Pentode and depth in the soundstage was better. Instruments more articulate. I had the bass at 1 o'clock due to the low end / size of the speakers but I must say, Hotel California live was really excellent.
Anyone else out thee have the same experience? thoughts appreciated.

Without exception, I have found the more powerful amp to sound better than the less powerful, all other things being equal. Effortless headroom and transients make a subtle, but quite substantial difference that cannot be achieved any other way. With tube amps the difference is more subtle than SS amps, of course and for obvious reasons.

This assumes, of course, that the amps in question are of at least similar overall quality.

in my 35+ plus years of experience, I've never heard of anyone with a PP amp who liked triode mode better than pentode or ultra-linear mode.
Triode mode is for people who have WAY too much $$ and not enough common sense, so they've purchased a 2 watt amp for $5000 along with $5000 speakers
and listen to the magic that they think they purchased. Sorry, not meant to offend anyone, just my opinion and experience.
Triode is very clean, no feedback, but limited frequency response and limited dynamics. Like a decent $30 transistor radio.

With my M125's I prefer triode mode, but that was not always the case. When I was using strictly tube amplification I preferred UL mode. Then I converted to biamp, and soon after triamping; top and bottom via SS using tubes in-between. Now I prefer triode mode. But my setup is not typical.

I think one of the good things (among many) about VTA amps is that you have a choice. If the triode mode was not a switchable choice from pentode, the latter of which I also prefer, there no doubt would be a cacophony from those who wanted said option.

Comes to the bottom line:

Triode Mode has limited headroom. In applications where headroom is not necessary or required (two different things), its 'other' advantages may show. Otherwise, not so much.

That there is an exception to the general rule of thumb as it applies to power: More is Better; should be a surprise to no one. But it remains an exception.

Horses for Courses.

Peter W. wrote:Comes to the bottom line:

Triode Mode has limited headroom. In applications where headroom is not necessary or required (two different things), its 'other' advantages may show.  Otherwise, not so much.

That there is an exception to the general rule of thumb as it applies to power: More is Better; should be a surprise to no one. But it remains an exception.

Horses for Courses.

MORE POWER!
Peter W., are you really Tim the Toolman incognito?

I do keep two "Binford" power amps.

http://www.vintageaudioaddict.com/harman_kardon_citation_16/harman_kardon_16_reduced16.jpg

https://www.picclickimg.com/d/l400/pict/173698886336_/Harman-Kardon-Citation-Nineteen-19-Amp-200-Watt.jpg

The former drives the Maggies. The latter drives the big ARs in my "radio room".

I knew it!
By "radio room" do mean ham-shack?

deepee99 wrote:I knew it!
By "radio room" do mean ham-shack?

Nossir.

It is the smallest "bedroom" in the house, second-floor rear that I have taken over as the room that houses my bench, projects and "stuff". That it also has two walk-in closets (full) helps. 16 x 12 x 9 and windows on three sides.

I need to do some serious culling of the herd.

OOh; I have one of those. One side bias is off somewhat. The bias method is hard to implement with old hands and eyes. Any tips? Why call it Binford?

bongoman wrote:OOh; I have one of those. One side bias is off somewhat. The bias method is hard to implement with old hands and eyes. Any tips? Why call it Binford?

It was Peter's response to my wondering if he was Tim the Toolman Taylor.
Other than that, I've no clue how to bias a sand amp.
Peter, we try and try to cull, but that just gives us room for more audio stuff. It's a fool's errand.

Sorry I don't know how to specify which post I'm replying to yet. That was mean't for Peter W. I like the Citation 19 myself.

bongoman wrote:Sorry I don't know how to specify which post I'm replying to yet. That was mean't for Peter W. I like the Citation 19 myself.

The bias is not difficult - but the access might be as clearances are tight. Excellent light is your best friend.

Manual here:

https://manuals.harman.com/hk/Service%20Manual/Citation%20Nineteen%20sm.pdf  

"How to" set the bias (idle current) is at the bottom of Page 15.
It is *!!IMPORTANT!!* that you use a True RMS AC/DC meter when you do this.
Note  that the 19 (and 16) are actually two separate amps in the same chassis, so what goes for one side should also go for the other.

Now: Being in the belt/suspenders/Velcro mode, and as you are 'in there' anyway, it pays to lubricate the pots (all systems off) such that you are not hitting a dry spot and getting a false reading. Shorting the inputs is also good for the no-input condition. Follow the cautions as well. Take your time, knowing that you are good for another 30 years or so when done.

Similar for the 16, but there are two (2) pots to mess with (per channel) in that beast.

"Binford" was the brand of tools in "Home Improvement" that featured such things as a V8-powered riding mower - and their motto was "More Power".

I keep a variety of power and integrated amps including AR, Dynaco, Harman Kardon, & Scott (LK150), tube and solid-state. The two HKs are for the difficult speaker loads.

Peter W. wrote:

bongoman wrote:Sorry I don't know how to specify which post I'm replying to yet. That was mean't for Peter W. I like the Citation 19 myself.

The bias is not difficult - but the access might be as clearances are tight. Excellent light is your best friend.

Manual here:

https://manuals.harman.com/hk/Service%20Manual/Citation%20Nineteen%20sm.pdf  

"How to" set the bias (idle current) is at the bottom of Page 15.
It is *!!IMPORTANT!!* that you use a True RMS AC/DC meter when you do this.
Note  that the 19 (and 16) are actually two separate amps in the same chassis, so what goes for one side should also go for the other.

Now: Being in the belt/suspenders/Velcro mode, and as you are 'in there' anyway, it pays to lubricate the pots (all systems off) such that you are not hitting a dry spot and getting a false reading. Shorting the inputs is also good for the no-input condition. Follow the cautions as well. Take your time, knowing that you are good for another 30 years or so when done.

Similar for the 16, but there are two (2) pots to mess with (per channel) in that beast.

"Binford" was the brand of tools in "Home Improvement" that featured such things as a V8-powered riding mower - and their motto was "More Power".

I keep a variety of power and integrated amps including AR, Dynaco, Harman Kardon, & Scott (LK150), tube and solid-state. The two HKs are for the difficult speaker loads.

Peter, Whaddya think of Carver's TFM series? I remember enjoying my TFM-45 thru a pair of Dahlquists. There's one being sold for parts on Fleabay at the moment and from the sound of things, it just needs new caps. I'm no Carver fanatic but every now and then he comes up with aces. Functional TFMs are still selling in the $500-$1,000 range.

Thank you for  the manual. I did have a copy but  it's good  to have another source. You nailed it; the clearances are a little tight. I'm wondering if a solid 40 watts in triode would not be adequate to over come some of the disadvantages? I mean with efficient speakers... what are we idling at? Unless it's a large room or you listen to doom metal at bone crushing levels. Does triode mode round off the freq. extremes? Or is a true triode tube better suited for a triode wired circuit.

Well, with my VTA ST-70, Klipsch Heresy III speakers, and original output tube choice I definitely preferred Triode mode. So you know at least one person now Roy

UL seemed too bright. I recently discovered it was at least partly due to my tube choice though. I originally had Mullard reissue EL34s, and when I swapped them for JJ tubes I was so much more impressed with the sound. The Mullards had a nasty mid range bite that did not get along well with that particular amp and speaker combo in my room. Triode mode helped tame this. I still find I like both modes. It's nice to have a choice.

Mpffff... First, let's get Carver out of the way. I have limited experience with Carver products. But, in the words of Henry Longfellow:

There was a little girl,
           Who had a little curl,
Right in the middle of her forehead.
           When she was good,
           She was very good indeed,
But when she was bad she was horrid.

Klipsch speakers are quite efficient. And would respond well to a low-power amp, and quite well to about any of the VTA line in a reasonably sized room even at substantial levels. They are also merciless.

I have blathered before on Headroom and Transient Response (these are separate but related). And, whereas tubes do sound different across brands, lots and the time of day they were produced (these days), I suspect that the brightness you describe is the amp responding to transients allowed by performance of that particular tube choice and into those speakers (see: Merciless). Triode mode scraped those transients away, as did another tube choice.

De gustibus et coloribus non est disputandum.

Thanks for the lubricate the pots hint. What I needed. Such a small nudge on that pot to make a big difference. I'm using my Fluke 115 multi-meter. And shorting plugs. Ever do any caps? Maybe in the PS?

bongoman wrote:Thanks for the lubricate the pots hint. What I needed. Such a small nudge on that pot to make a big difference. I'm using my Fluke 115 multi-meter. And shorting plugs. Ever do any caps? Maybe in the PS?

Believe it or not, across now five (5) Citation products, only the C17 pre-amp has needed filter caps (and the reed relay). The C18 (tuner) needed three (3) op-amps and ten (10) small electrolytics. The 16 and the 19 filters all ESR and Test 'like new', separately and in-circuit. I have also had C14 & 15 tuners that needed cleaning, lamps and tweaking, but no caps.

Note that both the 16 & 19 are notorious for broken leads at the input jacks. The wires are very short, and I expect that the flexing associated with plugging and unplugging stresses the connections. It is this failure that allowed me to get both units in otherwise pristine condition for less than $150 each. I repaired several of this line at the Clinic at Kutztown over the years, so I suspected that this was a good explanation for these amps when described as 'intermittent'.

I also have a 17 pre. That one works well now but I will replace caps as a matter of course. Unfortunatley; it's the eq version. The summer system. Tubes get too hot; my CAC works too hard. Broken leads and the tight clearance on speaker jacks. Thanks again.