Review: Classic Dynaco Tube Amps - Upgrades and Mods

Tube be or not tube be... sorry... couldn't resist. The picture you see here shows a pair of restored, original factory assembled Dynaco Mk III amplifiers. I purchased this pair from a neighbor who had them stored in has garage. He needed some cash and I was looking for some tube equipment to sweeten up my stereo system.

With a little help from my friends I cleaned up these amps, replaced old selenium rectifiers, installed new power supply capacitors and of course installed all new tubes. James Demeter and Kevin from DynakitParts.com were both generous in providing their expertise and encouragement. Kevin also supplied replacements for the original Dynaco can type capacitors. These replacements increase the capacitance and voltage rating of the original power supply caps. That makes the power supply safter and it also give you a performance boost. Kevin sells complete kit amps that are excellent replicas of the original Dynakit amps. Like the original Dynakits the prices are reasonable and the quality is first rate.

Dynaco amps were some of the most popular hifi amps ever sold. Their popular models include the Stereo 70, Stereo 35, Mark III, and Mark IV. These amps were sold factory built or as kits. I was fortunate to get a pair of the 60 watt Mk III amps that were factory built. The original workmanship was good and they didn't need a whole lot of work. The sound of these amps is lush and sweet. You know right away these aren't your typical transistor amplifiers. Voices and instruments take on a three dimensional quality that brings the music alive.

There a folks such as self-proclaimed Dynaco guru Dynaco Doctor aka Joe Curcio who will tell you that the Dynaco amps perform poorly unless modded. Curcio audio has for sale a number of "upgrades" that he promises will allow you to realize the "full potential" of your classic Dynaco amp. It makes me wonder how these amps became bestselling classics in the first place without any help at all from Mr. Curcio and his fellow tube gurus. Could it be that they sound pretty darn good with the stock circuitry designed by David Hafler? Are the commercially available mods really going to sound better than the classic Dynaco sound? 

My buddy Dennis and I have, between us, built most of Mr. Curcio's designs and we've each been disappointed with the final results. The tube magic was lost. The modified amps may measure well but they they sound somewhat cold and uninvolving. It's also worth noting here that the Dynaco amps are collectable and that they are most valuable in their stock form. Perhaps monetary value is significant as an indicator of optimal sound quality–it depends on who you listen to.

Curcio is now advertising some newly designed mods. He says these mods will preserve the tube sweetness of the original Dynaco circuits. We exchanged some emails and he persuaded me to place an order. However, after thinking it over, I cancelled the order and opted to keep my Mk III amps stock. The 6922 tube driver stage favored by Curcio may be accurate and may measure well, but 6922 tubes tend to sound cold compared with the original Dynaco drivers. If you're dead set on modding your vintage Dyncaco amps, there are a number of popular mods available these days. You can do some Googling and you will find the commercially available Curcio Audio mods, the Roy Mottram mods and the Poseidon mod plus all kinds of DIY mods. 

In my opinion, David Hafler got some things very right in the original Dynaco designs. Therefore my advice is to do only what is necessary to keep them running well and then sit back and enjoy the magic. (By the way, be warned... when I cancelled my order for Joe Curcio's Mk III upgrades, he deducted a whopping twenty percent "restocking fee" from my refund. When I complained about that his response was adversarial bordering on belligerent. He doesn't deal with returns graciously.)

I'm using a Conrad-Johnson PV5 preamp and my Mk III amps to drive a pair of Thiel CS 2.2 speakers. While Thiel's are not considered to be especially tube friendly these CS 2.2's sound great with the Mk III's. There is plenty of power to spare. 

If you are fortunate enough to own a pair of Klipsch horn loaded speakers, you should seriously consider finding or building a tube amp. Many music lovers consider Dynaco and Klipsch to be the path to musical nirvana. Kevin from Dynakitparts.com tells me the Dynakit Stereo 35 paired with some highly efficient horn speakers is some of the best sound he's ever heard. The Klipsch forums are another good source of info about Dynaco amps.

The original Dynaco designs are among the best tube amps ever made. You can buy better tube amps, but you had better be prepared to spend a whole lot of money. If you absolutely must have the best of the best and you can afford it, then look for some Conrad-Johnson tube hifi gear. If you are willing to believe that you can convert a Dynaco amp into an amp that rivals the very finest amps that money can buy then Joe Curcio and the other Dynaco gurus will be glad to take your money. Although I haven't tried every possible mod, I would urge you to be skeptical of these claims. They sound too good to be true and in my experience that's usually a sign that they probably are too good to be true.

In the meantime consider this: In the world of tube amps, second best is still a darn sight better than just about anything else available. If you are fortunate enough to stumble across an old stereo Dynaco tube amp or a pair of Dynaco tube monoblocks my advice is to restore them, keep them as original as possible, and enjoy them for their classic sweetness and richness. I guarantee you will rediscover your favorite music and hear subtleties and shadings you never noticed before.

As a musician I believe that the perfect is the enemy of the good. Before you blow your hard earned money on expensive "upgrades", hear what the original Dynaco amp designs can do. I'm willing to bet that if you do that, you'll stop right there. It doesn't get much better. So save yourself some money, skip the mods, and spend your extra cash on some new recordings. Music is one of life's greatest pleasures and even more so when you play it through some great classic tube amps like the Dynaco Mk III's.

Alan Acuff, Folksinger

It occurs to me that I haven't properly introduced myself here on this blog of mine so here goes... 

My name is Alan Acuff. I entertained professionally for about twenty years. During that time you could find me pickin' and grinnin' at resorts, saloons, and cafes throughout Texas, New Mexico, Arizona and Southern California. I also produced national radio spots for Budweiser beer, opened for Bonnie Raitt, performed live on various public radio broadcasts, and when times got tough I worked at odd jobs here and there.

As a youngster I had an ambition to be a painter when I grew up. After high school I attended California Institute of the Arts where I wound up making video art instead of painting. I was pioneer in the early days of multimedia and performance art. In 2008 my art and music video's were feature by the Getty Museum and Research Institute in their landmark show California Video. They also interviewed me and included me in their book California Video: Artists and Histories.

In the early days of multimedia you couldn't make a living making music videos so after a brief stint in TV and radio advertising, I decided to pursue my interest in American folk music. In 1979, my good buddy Fred Walecki introduced me to Ramblin' Jack Elliott. Jack crashed at my Venice Beach pad for a while. 

Later on Jack returned the favor by driving me around Texas where he introduced me to Townes Van Zandt and Mickey White. Not long after that I started performing at Austin open mics. From there I progressed to bar gigs... I sorta got stuck in that rut for about two decades. Guess I should have been more ambitious but there I was playing the music I loved and making a living at it. Plus the joints where I played gave me cool T-shirts and free cheeseburgers. It just doesn't get a whole lot better than that.

Around 1981 I left Austin for Los Angeles where I studied acting, appeared in TV commercials and films, and continued to perform music. By 1987 I was suffering from a combination of Los Angeles smog and bad allergies. A doctor talked me into moving to Santa Fe, New Mexico where the  clean high desert air brought me some relief.

Pretty soon after moving to Santa Fe I was performing at the Santa Fe Hilton, the Bishop's Lodge, El Farol, the Coyote Cafe, and other local music spots. That's about as far as you can go in Santa Fe. Santa Fe didn't provide anything much in the way of other musical opportunities. So I returned to my art school roots. I took some photography classes and started a photography business. As a photographer I've worked for Car and Driver, Charter Bank, Lucchese Boots and many other clients.

Meanwhile some of my friends were encouraging me to study up on digital audio recording and to record some of the songs I wrote back in my checkered past. That's something I somehow never got around to in the old days. Could have been fear of success or just plain lack of ambition... I dunno... 

...and that brings us pretty much to the present. I'm just about finished converting part of my Santa Fe loft into a recording studio and then I'm going to make some recordings and videos which you'll find on my music website... coming soon! Please stay tuned!

This blog is a hodgepodge of memories, music reviews, and equipment reviews. It's dedicated to Ramblin' Jack Elliott and to everyone else who ever took the wrong road and just kept going because they were curious to see what was down the road and around the bend. I hope you'll enjoy visiting and reading, and I look forward to your comments.

Santa Fe Music Blog Update

Hi folks! Been too darn busy to post much in recent weeks. Just want to let you know that I'm making some progress and that I haven't forgotten all y'all. Stay tuned for some new music, some new equipment reviews, and more. As Ramblin' Jack Elliott always sez, "To be continued..."