Coincident Dynamo SE-34: SET amp with 300B's - initial impressions

(and hope I'm not thread highjacking but adding to the conversation)

 

You're going to love the amp with 50's/60's small group jazz - the 300B's are made for it.

I run a good preamp with my Coincident - Cary Audio SL-100 (SS), it provides plenty of gain to the Coincident amp.

Wouldn't want to mess with biasing myself - that's why both my PrimaLuna and the Coincident are self-biasing.

 

@Benzion Any new observations to add?

 

Been busy last few days, not much listening done. Will do some on the weekend.

 

I started a new thread seeking recommendations for another pair of full-range speakers.

Seeking recommendations for sanely-priced full-range speakers

One of the responders gave this link, the review in which rings very close to what I'm hearing with electric music. Incidentally, if you read through the music selections in this review, none are acoustic, and all are electric. So, I'm starting to think that it maybe the Zu's character mostly, and less the SET amp. @Erocka2000

Heco Direkt Einklang review | What Hi-Fi?

 

Update:

I have combined two systems in one room, one doing acoustic music only, comprised of:

Modded Pro-Ject Debut Carbon DC TT/Denon DL-301 /II LOMC cart/Lounge Copla head amp/ Pro-Ject Tube Box S2 phono;
Sparkler Audio Non-Oversampling DAC (Philips 1543) CD player;
Little Dot MkII headphone amp acting as tube preamp (with Rek-O-Kut 2-source switch for the two sources);
Coincident 300B SET power amp;
Zu Omen DW II speakers;

The other one doing electric music plus FM radio:

Denon DP-60L DD TT / Denon DL-110 HOMC cart / Prp-Ject Tube Bos DS phono;
Cambridge Audio CXC transport / DACMagic Plus;
Magnum Dynalab FT-101A FM tuner;
Brown Audio Labs LS-1B tube preamp;
Parasound 2250 v.2 SS power amp;
PSB Image T-45 speakers / Aperion super-tweeters;

Everything is connected to Furman power conditioner and APC voltage regulator.

The room now looks like this:



The SET amp is hiding behind the left speaker:



It's been a while since I've used the PSB speakers, and upon refreshing my memory I can tell they're not as warm-sounding as the Wharfedale 10.7's, and are more neutral in overall tone, with not so much bass extension. They're spec'd to 38 Hz vs. W's 30 Hz, and I can actually hear that difference. Overall, I can live with them, although I do like the W's sound better.

Now I need to install the W's in the living room and see how they sound there with the PrimaLuna Four amp. One snag - a banana plug broke on one cable, so gotta go get some before I report on that one.

 

Set amps are great if the rooms not to big and listening level is moderate. And, you have the right speakers.

 

Room is only 11 x 13, so it's just right.

 

Excellent. I dumped our real sensitive speakers and now have a few SET amps sitting around. I would try them with the different set up but 1.75w won't cut it.

 

Not all highly efficient speakers mate well with low powered SET amps. I have read that is the case with Zu’s, Avantgarde, and some others.

 

I can assure you my Zu's pair very well with my SET amp, however - for acoustic music only. For electric music the combination is not good. That's why I combined these two systems in one room. You probably already know that, if you've read this thread.

 

I see. It pairs well, except when it doesn’t pair well.

 

It would be great if you could arrange to hear another SET amp on your current system in order to make some comparisons to the Coincident amp.

I owned the Coincident 34se (el34 version) paired with Tekton Lore Reference speakers and later with restored Altec 9844 monitors, which were ~98db sensitive.

Comparing the Coincident to other amps (both SET and push-pull designs) on these speakers made it clear to me that the weak point in my system was the amp itself. Most notably, it sounded thin, harsh and anemic below ~300hz, and clamorous above 2k, compared to several other amps in A/B comparisons....Particularly on more demanding/dynamic genres like electronic, noise rock, etc.

Not sure how similar sounding the 300b'd version of this amp is to the standard el34 version that I owned, but I wanted to share my experience, having owned and spent time with the amp.

A/B comparisons convinced me that the Coincident 34se that I owned was not a great representative of SET (or even SEP) sound.

A 6 watt, 15 year old Art Audio PX-25, for example, trounced the Coincident in every sonic parameter I can think of.

I'm not trashing the Coincident - it sounded good with some kinds of music as you describe. But even on those genres it was inferior to other amps I compared it to.

My whole A/B comparison adventure with the Coincident started when I had to temporarily use my beater/garage amp - a 30 year old Denon receiver - in place of the Coincident. For all it's faults, the Denon sounded better.

 

It sounds amazingly good to my ears when playing Jazz, and just for that it's a keeper. For the rest - I got more gear/speakers.

 

Cool! I'm sure the 300b version sounds significantly better than the el34, and I forgot to mention that my Coincident 34se was the mk i.

I'm (fairly) sure I've held my tongue until now about my experience A/Bing the Coincident on the usual forums, but figured it might be helpful to you or someone else in the future.

 

I already had a push-pull amp running EL-34's prior to buying the Coincident, so buying another EL-34 amp held little interest for me, even if I liked the sound. The main reasons I bought the Coincident amp were the availability thereof with 300B's, glowing accolades from industry publications, and the reasonable price, compared to competition. For instance, Bottlehead charges more than I paid just for a parts kit of their Kaiju, then I'd have to find someone and pay him to assemble it. Others just charge insane prices, even the relatively unknown builders. So, Coincident just made sense to me.

 

I've offered before as to the Elekit, but if you buy a cool kit @Benzion, I'll build it for free for you.

 

Thank you, but I already have the Coincident - how many 300B amps can a man need? (Pssst, don't give me ideas now....)

 

Such a mensch!

 

My Avantgarde Duo speakers mate very well with my Berning SET amp with about 10 watts/channel. Stunning full-range sound reproduction with deep tuneful satisfying lows, realistic midrange, and extended highs. I must add that the room and set-up of the Avantgarde horn speakers are absolutely critical for optimal sound, and the process to discover the best set-up in any room (the larger the better for these speakers in my experience) takes time and patience. But once they are 'locked in', they are spectacular.

 

when i said "low power" i was referring to 2A3's, 45's and the like. 2-3 watts and lower.

 

I also have a Berning 1 watt/channel "personal triode amplifier" (using two 6SN7 tubes as power output tubes with each of the two inner triode sections of the tubes wired in push-pull to provide the output for each channel) that I tried with the Duos, and they sounded really good with it, full range, but only lacking in the dynamic power I get with my Berning "Siegfried" SET. Again, I believe the speaker placement has so much to do with the performance.

 

interesting, makes sense that with that sensitivity you should be able to drive them with anything.
not sure what the naysayers were basing their opinions on.