Ariels + Dynaco Stereo 70=?

[CamMan595]

I have been interested in building the Ariels for quite a while and now I am getting ready to take the plunge. I know next to nothing about tube amplifiers. I purchased a Dynaco stereo 70 amp off of Ebay and I have purchased a new driver board kit and a new capacitor board kit. I have two questions:

1) Is the Stereo 70 the appropriate type of amp to sound good with the Ariels?

2) Will it sound better with the upgrades or without the upgrades?

[zigzagflux]

That's what I use. However, instead of buying upgrade boards and supplies, I built the amp from scratch on a new wood chassis with steel top plate. As long as you use a good kit (might want to mention what you bought) the amp should do quite well. In fact, since you say you know little about tube amps, I would say you are doing exactly what you should do. You will learn a lot by tinkering with a ST-70.

Also, I built the ME-2 design, not the full transmission line design. I wanted to know if I would like the Ariels before I went to all the trouble of the complicated box. In summary, I am EXTREMELY happy with the results. Although I know little about tone and timbre (I can't tell you what 'key' a musician is singing, nor can I recognize what notes are played on a piano), I can tell the accuracy of reproduction is very good with the Ariels. My in-laws and friends are singers and musicians, who CAN recognize accurate instruments, and they rave about my system, simple as it is. And vocals......pure and sweet.

Few comments, then. I like to describe my Ariels as an accurate but delicate speaker. You won't get earth shattering bass and blink-your-eyes snare drums out of these speakers, but you will get, IMO, plenty of SPL for a normal listening room. My ST-70 is triode connected, so I am getting somewhere around 13W per channel. If you keep the UL connections in the stock ST-70, you'll get closer to 25W. I think this is plenty for the 91-92 dB Ariels. I would tend to steer you away from SET amps, in part due to your experience level, and in part due to the speaker efficiency. Again, you are heading in the right direction.

The Vifa woofers are out of production, but Madisound likely still has drivers available. Very affordable. Unfortunately, the Scan Speak tweeters have recently increased in price.

Under no circumstances should you go cheap on the crossover capacitors, especially for the tweeter. I speak out of experience on this one. I use Hovland, which I suggest (not to get into a big capacitor argument). Just don't go cheap; you will regret it.

And yes, you have a 99% chance that your amp will sound better with the upgrades. You will get better advice if you let us know what you got.

[CamMan595]

I got the "PWB-3U Driver Amplifier" from Curcio Audio. I also got the upgraded caps option that they offer for that board. The other upgrade was the "QUAD Cap Module - Below Chassis Version" also from Curcio.

If the woofers have such a wonderful sound, why would they stop producing them? Companies do the strangest things sometimes. I better buy the woofers now I guess.

And yes, you have a 99% chance that your amp will sound better with the upgrades.

I have no doubt that the amp will sound better but I'm wondering if the speakers were designed for the "old" sound and I will be correcting the sound that the speakers have already corrected for. I may be over thinking this.

Thanks for your input.

[DougL]

I have no doubt that the amp will sound better but I'm wondering if the speakers were designed for the "old" sound and I will be correcting the sound that the speakers have already corrected for. I may be over thinking this.

Lynn Olson has said that he tested the Ariels with multiple amplifiers types so that they would not be voiced for a single amplifier or type.
My advice is to go for it.

Doug

[Brett]

When I had my fAriels (V6), I used them with a large variety of amps and they were fine. An ST70 should make a nice match.

[zigzagflux]

Originally posted by CamMan595
I got the "PWB-3U Driver Amplifier" from Curcio Audio. I also got the upgraded caps option that they offer for that board. The other upgrade was the "QUAD Cap Module - Below Chassis Version" also from Curcio.

That will work quite nicely. Many on this forum have tried it with success.

Originally posted by CamMan595
If the woofers have such a wonderful sound, why would they stop producing them?

They are a fairly old design, and products evolve over time. What I would caution you on is don't try another woofer; the crossover is very specific to this driver. They are advertised as available at Madisound for $43.75. I have a very good opinion of Madisound; trustworthy retailer.

I like these speakers so much I even bought a complete set of spare drivers, matched from North Creek. They are sitting in storage. Who knows, maybe someday they will find their way into a transmission line cabinet.

[Lynn Olson]

The Ariels and ME2's work really great with either a stock or modified ST70 - I like to get a rise of out my audiophile friends by describing the Dyna Stereo 70 as the entry point into real high fidelity - anything less than the ST70, it ain't hifi no mo'.

This is easy to misinterpret. The ST70, despite its vintage and entry-level price "back in the day", is actually better sounding and more musical than most contemporary high-end audio electronics - and I include Audio Research and Krell in this category. Compare a slightly modified (wired in triode) ST70 to ARC's latest $7,000 confection and draw your own conclusions - just be willing to be thrown out of your local hifi boutique when you do this comparison.

It's a sad comment on how misguided the high-end has become that a humble ST70 is obviously better sounding than well-reviewed and heavily promoted "name brands". Of course, this is also true of humble Chinese amps like Shanling, too - compare them to ARC and Krell, and draw your own conclusions.

The ST70 serves as an extremely valuable "reality check" that's been around since 1958. It denoted the entry point into true high fidelity back then, and still has that role today, nearly half a century later.

Yes, you can do better than a ST70. Lots better. But aiming higher gets into serious SET territory, while the Amity and Karna are extreme-fringe audio by any standard, which is why I always discourage builders of these amplifiers.

In terms of refurbished vintage, the Scott LK150 is worth every penny, and then some. Refurbished Fisher receivers also sound wonderful, although some have the serious drawback of hard-to-get tubes, and assorted bias hassles with using different output tubes. Not a fan of McIntosh, sorry, and the advantage of original Marantz vs modified vintage is pretty slim. Also not a fan of Williamson amplifiers - Heathkit or otherwise.

Transistor amps are problematic. Most sound flat and 2D with Ariels, with muted tone colors and image depth diminished to almost nothing. Since vivid tone color and spatial realism is probably the greatest strength of the Ariel, this is a significant loss. A few transistor amps sound quite good, some very good, but I've yet to find any pattern to this, except maybe very high slew rate and moderate power (not too many output transistors).

For what it's worth, the Crown Macro Reference sounded quite good, against all expectation, along with the LNPA-150 (no longer in production). The Pass Aleph 3 didn't work at all, and I have no idea why. The Denon 2905 HT receiver I use for HDTV and movies is thoroughly undistinguished, although, to its credit, it's not as outright unmusical and harsh as most mass-market HT receivers.

In terms of keeping things simple, I'd go for the ME2's with a stereo pair of the Rythmik servo woofers - the Ariels and ME2's need subwoofers of very high quality. HT subs sound really awful, so avoid them. For the last 5 years, I've been using a REL Strata II, which integrates quite well with the Ariels - but I plan to take my own advice and get a stereo pair of Rythmik 12" servo subs.

[CamMan595]

Thank you Lynn. Your opinion means the most to me on this subject. I gather from what you said that I will not get poor results just because it was an entry level amp at the time of its manufacture. I am looking forward to building a set of Ariels soon.

[Brett]

Originally posted by CamMan595
Thank you Lynn. Your opinion means the most to me on this subject. I gather from what you said that I will not get poor results just because it was an entry level amp at the time of its manufacture. I am looking forward to building a set of Ariels soon.

The ST70 is a great amp, and the Ariels are excellent speakers; I only replaced mine when I moved to new digs with a huge room, and fell in love with horns. My experiments with ST35's and a lot of variants were also great and my Fisher 800B* receiver was one of the few times I've ever enjoyed just sitting and listeing to FM. When my mate finishes his (I gave him my second set of drivers) we'll also see how they go with SY's Red Light District amp.

For what the total will cost, you would have to go a long way further to better them.

* Note for Lynn. The EH 7591's are very decent tubes in the Fisher.