The magic of Ampzilla with Dahlquist DQ-10

[pkmaven]

When Saul Marantz and Jon Dahlquist created one of the world's most famous speakers, they used an amplifier with an odd name:Ampzilla. When James Bongiorno developed his Ampzilla, he declared that any true amplifier would have dual mono circuitry. His own system was a pair of Dahlquist DQ-10 with three Ampzilla II stacked on either side. (A total of 6 Ampzillas) Ampzilla II was a 200wp/ch brute with a vertical blowing fan which allowed stacking of the amplifiers. The fan's speed was governed by a rectifier held in place by a glob of silicone cement. Of the four feet on the amplifier, the right, rear screw was shorter so as not to touch the rectifier. Many people who had their Ampzilla amps "fixed" enjoyed them briefly until the right channel stopped working, because the repair person didn't know that the screw for right rear "foot" was supposed to be the short one! There is no dispute over the synergy of the Ampzilla II and the Dahlquist DQ-10a. It would seem that they were made for each other, and the sound is magical, so much so, that owners of the Time Aligned, Phased Array Dahlquist speaker couldn't tolerate the sound of any "box" speaker. Box speakers had no time alignment, and unlike the DQ-10a speakers, which were "mirror image", they all had a similar boxy sound. Adding a subwoofer to DQ-10s brings one to a much higher critical listening experience, and because the Ampzilla is a perfect amp/speaker match, they live harmoniously for a long time as "vintage" components. P.

[squeegy200]

Great Info.

I first encountered DQ-10s in college when working for Pacific Stereo. My boss invited me over to his house to listen to his setup. That's when I first heard them and always wanted a pair.

Fast Forward 20 years and I was browsing eBay and encountered numerous examples for sale. I eventually won an auction and ended up restoring a pair of sequential serial numbered DQ-10a's back to functionality.

I've since been lurking on several boards looking for more information on upgrades, tuning, and equipment recommendations.

I really enjoy the additional information provided by other Dahlquist enthusiasts.

[E-Stat]

When Saul Marantz and Jon Dahlquist created one of the world's most famous speakers, they used an amplifier with an odd name:Ampzilla.
I first heard John Cooledg'e's Ampzilla driving his Dayton-Wright electrostatics back in '76 or so. He was also reviewing the Thaedra and Thoebe preamps at the time. I worked for a Dahlquist dealer in those days and we had one customer with stacked DQ-10s driven by one.

Bongiorno is back and so is Ampzilla with an updated model.

rw

[squeegy200]

I recently read a magazine article regarding the introduction of the DQ-10s many years ago. The author met Jon Dahlquist at one of the big shows. At the time, the QUAD ESLs were the rage and the author entered Jon Dahlquists display thinking the DQ-10s were electrostatic copies.

He descibed his first experience with the Dq-10 phase array concept and I remember mention of the Ampzilla components.
What further intrigued the author is Jon had a pair of true Electrostatics in the corner of his display. Mr. Dahlquist would not demonstrate them and indicated they they were not yet ready for public debut. The outcome of those prototypes is unknown and they never made it into production.

[emaidel]

I use an Adcom GFA-5800 high current power amp to drive my DQ-10's, and am delighted with the result. I also supplement them with a Definitive Technology SF-15 powered sub, which blends in quite well (much better in fact than the previous DQ-1W with the Dahlquist Electronic Crossover and a superb Rotel power amp).

Adcom has replaced the 5800 with the 5802, which has even more power (300 watts instead of a "mere" 250 per channel) but it's now priced at over two grand. 5800's can be found on eBay for around $500 - a steal in my book.

[2325fan]

finally a man i like lol im runnin a marantz 2325 mated 2 to great american sound amps the match sounds killa my girl hates it an thats good lmfao

[dingus]

i cant remember where i read it (it was on the internet so you know its true...), and my memore is a bit fuzzy on the subject, but somebody said that Bob Carver designed some of his amps (thought it was The Carver Receiver, maybe it was Phase Linear) specifically for the DQ-10. can anyone shed some light on this?

[SAEA501]

Bob Carver designed for Phase Linear in the early 70s, the Phase 400 and 700. They were not necessarily designed for any specific speakers. Those amplifiers were pretty decent sounding but not the most stable things in the world. Their protection cicuitry consisted of smoke coming from the back of the amp. It was then you knew it was time to shut it down.

[squeegy200]

Bob Carver designed for Phase Linear in the early 70s, the Phase 400 and 700. They were not necessarily designed for any specific speakers. Those amplifiers were pretty decent sounding but not the most stable things in the world. Their protection cicuitry consisted of smoke coming from the back of the amp. It was then you knew it was time to shut it down.


Its funny you say that. I remember selling Phase Linears. The part I remember most is how often they ended up on the work bench in the repairs department.

[Lou Sleeves]

I have had the woofers re-foamed several times on my DQ10s, which I purchased in the early 1970's. More recently, I began hearing what I thought was yet another foam tear. However, the foam is fine. Instead, it appears that the last foam job did not center the paper correctly, and now the cone sags onto the speaker frame. In studying the problem I noted that the spider is quite concave rather than flat as it is on most woofers. Speaking with a technician, he suggested replacing the woofers altogether, and said he thought I could end up with stronger base, which as everyone notes is desireable for the DQ10s especially in light of the undersized box.

Does anyone have a suggestion for a well-matched woofer? Any other ideas?

[emaidel]

Do what I and others have done: contact Regnar in NY (a company that repairs and rebuilds Dahlquist speakers, and consists of former Dahlquist employees) and bite the bullet for the price ($139.50 each) for a complete rebuild of the woofers. I had my woofers refoamed by Simply Speakers in Fla. for only $80, but the job was a bad one, resulting in distortion at certain frequencies, and a rattle at others. After contacting Regnar, and having a long discussion with their service manager, Joe, I sent the woofers off, and got a call back from him describing in detail how bad the previouis job was.

After getting them back, I've experienced no trouble whatseover, and the overall sound of the entire system improved. They still don't go very low, which they never did, and augmentation with a good sub is essential.

$139.50 per woofer for a rebuild may seem steep, but after what you've probably paid for the "several" refoam jobs you've had done, it probably would have been the most economical from the start.

[Lou Sleeves]

I may do that. I was hoping to learn if there are superior 10 inch woofers on the market for the DQ10s. It sounds like the last re-foaming I had done had problems similar to yours.

They also "rebuilt" parts of the crossovers, but it appears they did a half-assed job at that as well. The sound was not much improved. Of course, the cost was high too.

[Feanor]

Its funny you say that. I remember selling Phase Linears. The part I remember most is how often they ended up on the work bench in the repairs department.

I had a Phase Linear 400 which used daily for 25 years with no problem other than that the meter laps burned out.

As I've always understood, the repairs are a result of abuse, most often driving them too hard and long without adequate cooling -- contrary to Phase Linear's specific advise.

[Dual-500]

I had a Phase Linear 400 which used daily for 25 years with no problem other than that the meter laps burned out.

As I've always understood, the repairs are a result of abuse, most often driving them too hard and long without adequate cooling -- contrary to Phase Linear's specific advise.
I used Phase Linear amps for many years in Pro Sound with excellent results as well as home audio.

Companies like Clair Brothers Audio built the largest touring sound/lighting companies on the planet using unreliable Phase Linear 700's back in the 70's, 80' and into the 90's.

Good thing they had the brains to ensure proper air flow in the racks - would have been a shame to have Sammy Hagar shut down in the middle of Heavy Metal on the VOA tour.

The model 700 series 2 amps that were custom built for Clair Brothers Audio had to spec a minium of 700 RMS per channel @ 4 ohms, both channels driven.

Here's a picture of one that survived the massive failures/burndowns they were "Known" to suffer. I am pleased to say, it's in my home audio inventory.

And yes to the naysayers - if you starve them for air - they will readily fry.

http://www.senorpanadero.net/uploader/userfiles/stevew/PICT1039%20%28Small%29.JPG

http://www.senorpanadero.net/uploader/userfiles/stevew/Clair%20Brothers%20%28Small%29.JPG

[blackraven]

Geez, I'm getting teary eyed from all the nostalgia.

[Dual-500]

Awe it's probably just the Mountain Cedar this time of year!

[yy17616433]

Your speech is very nice!

[rick489]

Has anyone heard of the Regnar brand? When the original Dahlquist company folded, the Service Dept. noticed that old customers still wanted their DQ-10s repaired rather than buy something new. So they opened their own company.

Besides repairs, they offer upgrade kits and a few new items. In 2005, I got all 3 DQ-10 upgrade kits and their own Center Channel speaker. Real nice!! Well worth the investment.

Find them at http://www.regnar.com/.

I am in no way connected to them. I just feel that classics should not be throw away. I'm real happy.

[hifitommy]

BUT a hafler 500 is just the ticket. the amp has TESTICLES and it grabs your dahlquists that way. the bottom end on them was deeper and more powerful using the 500 than on ANY other amp i ever heard driving them.

i heard them at sound center on ventura blvd, paris audio on van nuys blvd, and rogersound labs on van nuys blvd (possibly best there but more likely better at sound center). this of course was decades ago.

the hafler also made my fried RIIs shake the foundation of the house with no sub (didnt have one then). i wish i could have afforded to keep them and the hafler but i was raising my two youngest children then and my wife had medical problems. i was selling them for a friend.

[BOXMAN]

His own system was a pair of Dahlquist DQ-10 with three Ampzilla II stacked on either side. (A total of 6 Ampzillas) Ampzilla II was a 200wp/ch brute with a vertical blowing fan which allowed stacking of the amplifiers. The fan's speed was governed by a rectifier held in place by a glob of silicone cement. .

I am curious how do you run 3 ampzillas per channel on these speakers? I am not familiar with the Dahlquist DQ-10 speakers... are these Tri Ampable?? Please explain
Thanks!

[meltdown]

Forget it Boxman, you dont have a big enough electric meter on the side of your house. Besides the power company would have to cut out the seventh set of high pressure heaters and put more steam onto the blades of the turbine to push out the extra megawatts. More then likely the tub out on the pole in front of your house, would take off like a U2 rocket.

[BOXMAN]

Forget it Boxman, you dont have a big enough electric meter on the side of your house. Besides the power company would have to cut out the seventh set of high pressure heaters and put more steam onto the blades of the turbine to push out the extra megawatts. More then likely the tub out on the pole in front of your house, would take off like a U2 rocket.


LOL!!!!!!!!! Oh dont worry, I dont plan on tryin it..... but I am curious how you would actually hook it up.... ????????? Someone please explain.

[meltdown]

Well, I did it. I slid my MA6500 and MSD4 out of the way and slipped in my Gas Son Of Amzilla with a Theobe pre for my ML Sequel2's. Big Big difference. More dynamic and tighter base, much better imaging and power to spare. The Mac was laid back and the base was muddy. The Mac worked well with B&W's, even brought out the best in my maggies, but lagged when it came to the ML's. The Gas is much more cleaner and detailed, with crisp highs especially while listening to the blues. I hav'nt spun any vinyl yet, just running the Apollo for now.

[BOXMAN]

Well, I did it. I slid my MA6500 and MSD4 out of the way and slipped in my Gas Son Of Amzilla with a Theobe pre for my ML Sequel2's. Big Big difference. More dynamic and tighter base, much better imaging and power to spare. The Mac was laid back and the base was muddy. The Mac worked well with B&W's, even brought out the best in my maggies, but lagged when it came to the ML's. The Gas is much more cleaner and detailed, with crisp highs especially while listening to the blues. I hav'nt spun any vinyl yet, just running the Apollo for now.


:thumbsup: :thumbsup: :thumbsup:


Now, can you please tell me how to hook up 6 ampzillas to two DQ-10s...... I have even emailed James Bongiorno about this... he hasnt even responded!!!!!

[vocalium]

:thumbsup: :thumbsup: :thumbsup:


Now, can you please tell me how to hook up 6 ampzillas to two DQ-10s...... I have even emailed James Bongiorno about this... he hasnt even responded!!!!!

The maximum of "versatility" you can get with a pair of DQ10s is to hook to them up to 4 mono amps or a pair of stereo amps. This is possible only if you modify the passive crossover splitting in two parts. The first one, let say the low frequencies side, link together (with the already present x-over components) the Advent woofer and the cone woofer/midrange made by Philips. The second one is the high side with the remaining three speakers. It is like to biwire the system and in fact it is, so in this case you need an additional pair of binding posts (or the like) to accomodate the input for the second part.
I have done this mod and I did not like it, so soon I reverted to the original hook up. The main complain with this mod is that the sound is too much detached loosing both musicality and the sensation of "whole" IMHO.

[Dual-500]

:thumbsup: :thumbsup: :thumbsup:


Now, can you please tell me how to hook up 6 ampzillas to two DQ-10s...... I have even emailed James Bongiorno about this... he hasnt even responded!!!!!

Another option is to can the passive crossovers and convert them to an active system.

This option would apply only if you're a serious hobbyist with some test gear.

[squeegy200]

I recently acquired a Carver TFM45 and tried it with several of my speakers.

However, the DQ10s stood out remarkably more refined sounding with the Carver than my other speakers. It is a good match for the DQ10s

[barry2952]

$139.50 per woofer for a rebuild may seem steep, but after what you've probably paid for the "several" refoam jobs you've had done, it probably would have been the most economical from the start.

They are $175 each now, but they have a 3-week turnaround.

[hifitommy]

i will repeat my preference for the hafler 500 with these speakers. i had never heard bass come out of dq10s like that until the H500. definitely worth the effort to get one to try.

[emaidel]

They are $175 each now, but they have a 3-week turnaround.

A couple of years ago, a friend of mine came across a pair of DQ-10's that had been sitting around the college where he teaches, just collecting dirt. He was able to keep them, and I told him it would be very likely that the woofers would be shot, and, indeed, they were.

Rather than spend $175 each for a rebuild, I suggested he purchase brand new replacement woofers from Simply Speakers, adverstised as "upgraded Advent woofers." Instead of the masonite surround, there is a larger metal frame, and the foam surround is inverted. Nevertheless, he ordered a pair (at $123 each) and I installed them for him. They work just fine, and now, at least in my book, that would be the direction to go with older, rotted DQ-10 woofers, given the other problems besides rotted foam that can occur with speakers more than 30 years old. And, it didn't take three weeks to get them either.

[Feanor]

James Bongiorno, famous amp designer and principal of Ampzilla recently died. Rest In Peace, James

[barry2952]

Nevertheless, he ordered a pair (at $123 each) and I installed them for him. They work just fine, and now, at least in my book, that would be the direction to go with older, rotted DQ-10 woofers, given the other problems besides rotted foam that can occur with speakers more than 30 years old. And, it didn't take three weeks to get them either.


I'm in a position where $100 difference will mean little to me in the long run. I fall back on my classic car collecting mantra that I'm better off rebuilding a 40 year old part than trusting a new reproduction part.

When these speakers are rebuilt they use nothing but the spider and the magnet. Everything else is scrapped.

[emaidel]

I'm in a position where $100 difference will mean little to me in the long run. I fall back on my classic car collecting mantra that I'm better off rebuilding a 40 year old part than trusting a new reproduction part.

When these speakers are rebuilt they use nothing but the spider and the magnet. Everything else is scrapped.

Perhaps what it boils down to is whether or not one believes the DQ-10 woofer is indeed the same thing as the Advent woofer. The folks at Regnar claim there are differences, though several speaker repair companies have stated that, having had both Advent and DQ-10 woofers on their benches, they weren't able to detect any differences.

The current replacement from Simply Speakers is now $119, but out of stock. It claims to be an "upgraded", OEM, original Advent woofer. I know they work well, having installed them in my friend's DQ-10's.

Insofar as the Regnar rebuild, I'm fully aware of the extent of the rebuild, having had a rather long discussion with their service manager there when I had mine rebuilt, after an especially sloppy refoam by, of all places, Simply Speakers.

So, this is not an endorsement of Simply Speakers, but a suggestion for an "upgraded" woofer for less money than a rebuild of an older one.

[barry2952]

Woofers should be back from Regnar today. The capacitor kit and wiring upgrade mad a big difference in sound quality. I quantified this by only doing one speaker upgrade and listening to both. Even switched outputs to confirm that it wasn't the other electronics.

Took my meter section out of the Ampzilla and sent it in for repair after my cleaning of the switch only lasted a few days.

I'm thinking about using 12" cinder blocks as speaker stands as mine are falling apart. Any feedback on that plan?

[barry2952]

I tried the cinder blocks and they look just like I'm using cinder blocks as speaker stands. I will build some nice Teak veneer boxes to enclose their ugliness.

The woofer installation went well. They sound just fine.

http://i244.photobucket.com/albums/gg18/barry2952/IMG_1819-1.jpg

[barry2952]

Built some surrounds for the speaker stands.

http://i244.photobucket.com/albums/gg18/barry2952/IMG_1843_zps177ed869.jpg

[barry2952]

Michael Bettinger did a great job fixing my meter and making me an LED harness and lamp for the power light. The refurbished DQ-10s sound great.

My wife is a choral singer and pianist and she marvels at how it sounds like you're at the concert as soon as you close your eyes.

Thanks to Regnar and Mike Bettinger for helping me bring music back into my life.