Model 19 with SET or P-P Tube Amps

[selmerdave]

I think it depends largely on your taste, and partly on your exact listening situation. It's safe to say I think that a .75W 45-based SET amp is not going to shake the walls of a 25 x 30 room with ANY speaker, but even that will produce a reasonably good volume I would guess. SET is about the magic and clarity that comes with the simplicity and purity of the ciruit design, and if you haven't heard it before hearing it might well change your priorities (as it did mine). An 8w/ch 300B SET should give you considerable volume from most Altecs (more than 100db with good dynamics), but it won't pound your heart from 20 ft. like a 30-watt PP will with the same speakers. On the other hand, the PP doesn't have the purity of SET.

Having said all of that, just as important is WHICH equipment you use, ****** SET amps won't sound good with any speakers, and the finest PP amps will give great detail. The nice thing about Altecs aside from sounding wonderful is that the efficiency allows for less of a tradeoff with the SET. Good luck!

Dave

[selmerdave]

In the last paragraph I don't remember what word I used but I certainly didn't expect it to be censored, I meant to say "poor" or "lousy" SET amps.

Dave

[selmerdave]

Oh, as for a suggestion I'm using a Decware SE84C SET ($499) from www.decware.com that I am very pleased with (since upgraded sonically for less than $40 to the Select model). It's a fine company that I have no problem recommending. Their amps will do better with the 8 ohms of the Model 19, but mine sounds great in my small listening room with my 16 ohm 604E's. The OT's on these amps have only a single tap.

Dave

[Martyh]

I dont have much experience with Altec speakers in the home. Mine are still in the design stage (with some great help from the people on this board I might add). As to the best inexpensive route into tube amplification, you might try scrounging up an old PP 6BQ5 receiver or integrated amp. You can still find them pretty cheap and the 6BQ5 is a great sounding tube. Most will do about 15~17 watts AB1, this is enough power to experiment with most dynamic speakers. If you like the sound enough to start down the path of no return you can triode connect the output. Step two would be to strip out the transformers and scratch build a triode amp with a better front end than you will find in the typical amp of this type. Something like a 6BX or 6BL7 for the output will make a great little amp for not allot of money. You can get about three watts class A PP out of these tubes into the typical 8~10k load of the BQ5 transformers with very low distortion. If your speakers work well with this power level you can try the SE gig with a bit of confidence. The whole trip from el cheapo integrated to PP A1 triode can be made for a few hundred dollars and a bit of work, less than the cost of one top shelf SE transformer.

Marty

[Altec19]

Greetings All,

What experience has this esteemed group had with Altec Model 19's (or similar) and low wattage tube amplification? Does a 2 watt single ended triode amp prove to be adequate? Is a slightly more powerful push-pull amp worth the extra wattage versus the move away from pure class A operation?

Any suggestions for an inexpensive introduction to tube amplification?

Thanks, as always!

[joyspring]

Hi Altec Fan:</p>

In my opinion, your main criteria is sufficient amplifier power; whether the amp is single-ended vs. push-pull, or even tube vs. solid-state is of far less importance.</p>

Despite the high sensitivity of the Model 19, it's probably wise to remember the extreme headroom of newer 20/24-bit digital sources with upwards of 20dB peak-to-average.</p>

Transducers (whether microphones, loudspeakers, phono pickups or tape heads) and source material definitely constitute the largest improvement to any audio system and in my estimation, you've made the greatest improvement simply by replacing your former loudspeakers with the Model 19s.</p>

OTOH, amplifier design is hardly a black art -- more specifically overcoming silicon forward voltage is so well understood that even a second-year EE student can design a push-pull amp that has practically nil (and definitely inaudible as has been proven time and again through blind testing over the past thirty years) crossover distortion. Heck, power- and line-level amps are practically black boxes of gain nowadays ;-)</p>

Now for my rant:</p>

Find an amp that has more than enough power, perhaps a lot more with the current proliferation of 24-bit titles and in the interest of protecting your HF drivers. Ensure that it has a flat frequency response with inaudible distortion at its rated output and can readily handle any reactive load that the Model 19s may present. All this essentially constitutes the Federal Trade Commission's amplifier advertising guidelines in the B.R. era (Before Reagan), but that's another story entirely...</p>

Anyhow, this criteria may be met by many sub-$2000 amplifiers (and many sub-$1000 amps and even integrated receivers!). Bryston, Hafler, Crown, McIntosh, BGW, Crest Audio and Yamaha are reputable companies with competant engineers that immediately come to mind...</p>

Use that extra money you didn't hand over to a tube/SET boutique outfit with utterly incompetant engineers (there are *far* too many of these!) whose main design philosphy is the use of *more* boutique items (capacitors, silver wire, etc.) and *spend* it instead on CDs/SA-CDs/DVD-As, tickets to live performances, donations to your local public radio station... anything that ensures that the art of music will live on.</p>

Hope you enjoyed this rant and definitely hope it imparts an alternative view regarding the purchase of your new power amplifier!</p>

BobR</p>

[AllanCT]

I'd have to agree with BobR however I don't speak so good.

[Altec19]

It's always welcome and informative to hear the perspective from both sides of an issue. There are valid points to be considered with both tube and ss amplifiers.

Over the years I have owned efficient and not so efficient speakers. The 19's are the highest thus far. I've bought and built various FET and bi-polar amplifiers, some that sounded very musical and others that were serrated-knife-through-a-beer-can harsh. My current ss amp is about 200 watts/side and reasonably listenable. It just occurred to me that I could have some fun with the 19's efficiency and once again put to use the vacuum tube training I received in an earlier lifetime. I think I like MartyH's idea. Just for kicks maybe I can find a vintage Dynaco (perhaps with 6BQ5 outputs) and start there. If I like the sound maybe a SET amp next. I don't intend to abandon my current ss amp, just try something different with the 19's.

Thank-you again, Gentlemen. I appreciate your thoughts and guidance.

[selmerdave]

Well, BobR and AllanCT are free to have their own opinions, but I can tell you that most people who own tube equipment are those who realize that 10 watts out of one amp is not the same sound as 10 watts out of another amp and therefore the amount of rated power is really of minimal consequence. I would in particular NOT recommend a high power solid state amp as the high efficiency of the Altecs will have them operating at very low power most of the time (less than 1 watt) which is where these amps operate the poorest. I can tell you from my experience that 1.2 watts per channel with my 604E's (100 db/1w/1m) is sufficient to produce great dynamics, great bass, etc. at levels my neighbors can hear. In addition, $500 for a complete amp that will rival many costing 10 times as much is not a major investment, or at least it is unlikely that you will get a decent amp for less. Also FWIW a friend who has been listening to Dahlquist DQ-10s for 30 years with a Bryston 4B recently told me he is considering replacing it with a Decware amp after hearing my setup.

In the end, to each his own.

Dave

[blakehoo]

I really should not be posting this, but as a "heads-up" to the group...Transendent Sound has developed a new SET...that is also OTL !! This was developed specifically for ALTEC professional and VOTT high efficiency horn driven speakers.
At home I have 16 ohm 299's and 416's in 828's, powered effectively by "flea powered" SET's.
These should be dino-mite!!!

This is the link: < http://www.transcendentsound.com/single%20ended.htm >

I have already ordered a set, (and my credit card will not bill until they are shipped.)

Let me know what you think