Tube Integrated - Narrowed down to 4 - Help pls


Hi gang,

Ok, speakers are a custom-made, Great Plains Audio (Altec) 604 based system, with BSC filtering that leaves the sensitivity at around 96bB-97dB....

I'm moving from a Parasound A-21/Sonic Frontiers SFL-1 combination, to a tube integrated....All of my prior speakers were hideously inefficient, hence the big power SS amp...

Here's my list of finalists:

Rogue Tempest
Rogue Cronus
Cary SLI80
Cary CAD300SEI

The 300SEI is the odd man of the bunch of course, but I'm still on the fence about going SET or not....I do want the "magic," but my listening preferences (live volumes at times) and living space (15 x 30) are concerns....If SET is the only way to go, then I can rearrange the room for more of a near-field listening environment (6' from the speakers). Regardless, SET is still a consideration if folks feel it'll work....

I'm looking for as much of the midrange sweetness of an SET that I can get, and I'm also a sucker for soundstaging, imaging and super high levels of detail....Add to that, I like dynamics and a good, solid foundation....I may be off base, but unless I spend a fortune on a 300B amp with massive iron, I don't think I'll get the "punch" in the low end that I like...I have zero experience with tubes, so I could be all wet...All I know, is that when a bass pedal hits a bass drum, I want it accurate, and not like a pillow...

I know there's 10,000 other options, but I've narrowed it down to these 4, so if you'd be kind enough to limit your input to the above mentioned products, I would greatly appreciate it....

So the million dollar question: Which one, and why?

Thanks so much for any input!!! I have zero options in my area when it comes to tube equipment, so I'm flying blind....
seadweller
You might consider looking for a used Cary SLI50, same chassis as the SLI80 but uses EL34's in pure class A push/pull for 30 watts a side. I prefer the sound of this amp to any SET or push/pull triode I have heard. The bass isn't tubby and it has a certain dynamic zip to it's presentation that is musically extremely compelling. I am using 89 db, 8 ohm sealed box speakers in a 10x14 room and it will play as loud as I wish to listen. Due to the class A operation it does make a lot of heat for 30 watts. I also think the chromed chassis looks much better than any of the painted ones used for the SLI80. Mine is not for sale!
hi,

Tube rolling continued.

Output tubes NOS: These tubes break the bank. The gold standard is the GEC kt88 but they cost $1600 a quad. Too much for me. I have and like the Tung Sol 6550 solid gray plates and you can find strong testing used ones for about 400 a quad and the cryogenically treated JAN-6550A GE 1985 at $600 a quad.

hope this helps

good listening

Larry
hi,

Tube rolling, if you do it you are about to take a ride down a long and winding road from which there is no turning back because its so much fun doing it.

I've rolled tubes in every position in my cary SLI80 from the rectifiers to the output tubes using current production and new old stock tubes (NOS).

Rectifiers: Some folks say different rectifiers make a big difference in the sound of the amp. I don't doubt them but in my experience I can't tell the difference various brands of nos rectifier tubes. Currently I'm using National Union 5u4gs. I've also tried Sylvania and RCA 5U4s and RCA 5U4GBs. I'd say pick the most reasonably priced nos tube and go with it.

Input tube ...6dj8, 6992, 7308, e88cc : This tube make a significant sonic impact in the amp. Some of the ones I really like are Mullard e88cc/6992, Amperex ecc88/6dj8, Siemens e82cc/6189 and Amperex 6992 PQ white or orange. The problem is these tube are becoming very expensive,hundreds of dollars per pair. A lot of folks like the current production Electro-Harmonix 6992 EH priced at 12.00 a tube.

Phase Inverter 6sn7: It does not have much of an impact on the sound of the amp. I have several different NOS brands because I use them in an AES preamp .. in the SLI-80 I've installed Sylvania chrom domes and they will stay there until they are tired.

Power Output tubes: IMHO they have the biggest impact on the sound of the amp. Presently I'm using Black Sable SED KT88s which are cryogenicaly treated SED KT88s. They are moderately priced for output tubes at $320 a quad are the best current production I've heard. Another current production KT88 I like is the Genalex Gold Lion KT88
Don't forget that horn loaded Altec is also reflex loaded and they were made before Mr Thiele gave us any of his math equations to help tuning. In retrospect the Altec bass was supplanted with a TC 2000 in a small suspension with an extremely dead cabinet powered by a big QSC which at least to me sounds quicker in the sense there was much less overhang, may be a better choice of words than "floppy" Perhaps the thin plywood Altec enclosures were a contributing factor and with your custom Great Plains boxes it will probably be much less so. You're also right could be the 16 ohm loading, the Cary is switchable from either 4 or 8 and can be done on the fly and the difference between the two is hearable, again I think your GP 804's are 8 ohm so this should remove one more variable from the equation. As far as either Rogue or any SET amps I don't have any experience.
Thanks everyone.....

Something that's interesting, is some folks get fast/tight bass out of the SLI80, and some get slow/flabby bass.....Funny thing is, the slow bass is coming from speakers you'd think would have fast bass, and vice-versa!!! I would think it's amp and speaker matching, but I had both Thiel 2 2's and 3.6's, and they require some grip for the low end...

It's also interesting to hear of floppy bass out of an A7, particularly with the horn loaded woofer...The cones are lightweight paper, with huge magnet structures....Could it have been that the 16ohm impedance didn't mate well with the SLI80?

Which unit do you believe would respond best to tube rolling?
I used a Cary SLI80 F1 for a while driving a vintage pair of Altec A7's and found it to be entirely adequate. My Altecs were 16 ohm and still there was enough power even in triode mode. The bass was strong but a slight bit "floppy" but I think this is the characteristic of the large paper cone woofer. Remember when these speakers were first brought out that a 20 watt amp was huge. The Cary can use either 6550's or Kt 88's with just a bias adjustment which is straight forward and quite easily accomplished. If you buy a Cary on A'gon and don't like the signature it should be an easy sell as they never seem to last too long. Happy hunting.
I had a Rogue Cronus and enjoyed it a lot. It was the first EL34 tube amp that could play bass effectively enough for live rock or big orchestral music. I have also had a Cary SLI-80 and it had a fantastic midrange, but just couldn't get the job done when bass was required (IMHO). One other kewl thing with the Rogue is you can play with different output tubes - KT77 and EH 6CA7 work as well as the EL34s... does make a minor difference in sound.
Hi,

The speakers will work with both PP and SET amps. I am a little concerned with the size of your room with just 8 watts with the 300B set amp.

I do have a both a PP ( Cary SLI 80 with Thiel 2.4 speakers) and a SET ( Wright Mono 3.5 amps and Klipsch Cornwall speakers ... 103db efficient). I enjoy both systems imenensely and won't even venture a guess which is better. They surely are different.

As to bass response, the Cary/Theil has very tight fast bass. The SET system has floppy bass in the lowest octave... but we buy SET systems for their midrange magic not for deep bass.

The Cary is a great amp IMHO and it sounds great in the triode mode where it put out 40 to 50 watts. If you get it, you will not be disappointed.

good luck with your choices,

Larry
I have seen the ocassional PS Audio GCC-100 for sale. See the reviews comparing it to expensive tube amplification. And it's GREEN, being 85% efficient saves electricity
I second the alamarro 318b.A set amp will drive these speakers to very loud volumes.You will not need near field listening.I have heard the altec's with 8 watt 300b's and they were loud and sounded excellent.When the Altec were designed and made they did not have big amps.Twenty five watts was a large amp back then.It is up to you.KP
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Almarro 318 it is a tubed set intigrated amp with I think 18 watts at apprx $2000 new,myself I am looking to find a used 205 almarro 5 watts,these amps are very well reviewed but better than that they are very hard to find and they go fast so if you don't like it you can sell it easy,check out google for a 6 moons review,Nick
Just pick the one you like. Nobody but you and a Sig Other is rellevant. We can't know what you would enjoy most, we can say what we like most but what I like doesn't matter at all. Anyone who claims to have a monopoly on the correct sound is quite frankly Full Of Sh**.