Speakers for tube pa-amp??

Jussi Huhtakangas · Post by **Jussi Huhtakangas** » 5 Mar 2003 10:54 pm

Does anyone have any experience/suggestions of what kind of speakers would be ideal to use with a tube pa-amp. We have a German Dynacord MV120 six channel 100 watt ( four EL34's )amp. It was built in -60 and should be a top of the line gizmo of the time, was widely used in theater and auditorium amplification also. It's in great shape, never been modified in anyway. There are speaker inputs for both 8 and 16 ohms. Would a couple of speaker cabinets loaded with regular good "guitar" speakers work? We're intending to use it as an optional rig for the club gigs ( we do have a regular "modern" sound system too, so I don't need to hear how much more reliable they are

). Any suggestions? Thanks in advance!!!

David L. Donald · Post by **David L. Donald** » 6 Mar 2003 8:04 am

Speakers; depends on what your going to use them for. You say optional system for clubs... Is this for making the PA more powerful?

Is that 6 100 watt channels???
100w is not much for PA work, of you put 1 100w speaker on each channel this would be fine. More and you might hit clipping faster.
But tube amps clip smoother than transistors.

You can push this amp harder for the output for paper mids like some 9" upper mids.
As extra woofers, you'll most likely go thought the power real fast.
As long as the combined impeadance matches the amps outputs yout fine

Erv Niehaus · Post by **Erv Niehaus** » 6 Mar 2003 1:07 pm

I have a couple of PA systems. The last speakers I picked up were a couple of Peavey 15" wedges w/volume controls. They can be used as monitors and also have the screw plate on them so they can be placed on speakers stands. Very versatile.
Erv

Jussi Huhtakangas · Post by **Jussi Huhtakangas** » 7 Mar 2003 12:51 am

The amp has six input channels; three for microphones and three line inputs ( for reel tape recorder, turntable and what had you in -60 ). Keep in mind, that the way how PA-amplification was used in 1960 was very different from how it is done today, the equipment was not designed for multiple mics on drum kits, for example. The idea is to use these three microphone inputs for vocal mics and let the rest of the band bleed into those mics. Think how bluegrass bands were amplified back in the old days, for example. So we're not intending to mic individual amps or instruments, more like using the vocal mics as ambience mics. With the optional use, I meant the venues, clubs and bars where this kind of sound system would work ( actually most of our gigs are in places like that ). Also, the 100 ( tube ) watts this amp produces is equal, if not even more, than the solid state 300 watt 8-channel mixer amp we normally use. Just have to find the correct speaker configuration for it. Thanks for replies, guys

!

David L. Donald · Post by **David L. Donald** » 7 Mar 2003 3:23 am

Hi I think the apearance of equal power is the nature of tubes. When they distort it is smoother and less noticiable longer than your 300 watt. Which, when I goes to distortion, will sound much harsher much sooner.

Jussi Huhtakangas · Post by **Jussi Huhtakangas** » 7 Mar 2003 5:16 am

Yep David, I guess the distortion factor is why solid state amps require "bigger wattage". Also, judging by the size of the output transformer on this amp, I would say the 100 watts is definately "true watts", the tranny is huge! If you go to www.dynacord.com and click "about/history" you can see a picture of MV120, it's the one that looks like an old Pontiac dashboard

.[This message was edited by Jussi Huhtakangas on 07 March 2003 at 05:23 AM.]

James Quackenbush · Post by **James Quackenbush** » 10 Mar 2003 7:54 am

Jussi,
Since you are using this amp for 3 microphones, and using it for voice and not instruments, you can use any kind of PA cabinets with a 15 inch speaker and a horn, or a 12 inch speaker and a horn, for a full range sound for vocals...One cabinet on each side..
100 tube watts is plenty for small/mid sized gigs...The older Dynacord stuff is very high quality gear ... You could also use the other channels to plug a cassette or a CD player into while the band goes on break !!...Jim

chas smith R.I.P. · Post by **chas smith R.I.P.** » 10 Mar 2003 10:47 am

You might try Altec 417's for 12" spekers.

Chris DeBarge · Post by **Chris DeBarge** » 10 Mar 2003 1:04 pm

Why swim half the lake? Get some vintage movie theater speakers.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3012454384&category=3284

David L. Donald · Post by **David L. Donald** » 10 Mar 2003 3:34 pm

Got to love the design sense. Maybe a Merc. Montclair dash to LOL.
For speakers find the most efficiant you can. folder horn bass . You might look at Klipsches if you can find them. Take your handheld CD player and a stereo lead when you test the speakers. If it sounds loud with just the headphone output, and you like the sound It's reasonably efficiant.
I used to run my dad's Klipschorns on a 2 AA battery japanese transister radio and they were cool like that, and with a 15" woofer too.
At a party on a hill with them inside the volkswagon bus, hooked to the car cassette deck, I got a police complaint from 4 towns over in 1973.. now that's efficiant.
The cops thought I was mad... but didn't pull the plug, just said turn it down and turn the car north. LOL.[This message was edited by David L. Donald on 10 March 2003 at 03:37 PM.]

David L. Donald · Post by **David L. Donald** » 10 Mar 2003 3:39 pm

Chris the voice of the theaters weren't all that efficiant, But the general idea anyway. Interesting ebay link anyway

Jussi Huhtakangas · Post by **Jussi Huhtakangas** » 11 Mar 2003 12:28 am

Ok, now we're talkin'!! So, if I'd use a speaker like, say those Altecs, should I have 2 X 12" cabinets, or would just one per cab be enough? How about JBL D130F? We already have one of those without any use at the moment ( imagine that ).

David L. Donald · Post by **David L. Donald** » 11 Mar 2003 1:43 am

In general JBL makes very good products.
I would try the CD test on the JBL if you think it gets a reasonable volume, then with 100w tubes It should be OK.
"Speaker efficiancy" is your watch word for this amp.
Get very efficiant speakers and you will also get a warm tube sound, not distorted, and
usefull to you.
Inefficiant speakers and it will distort, make your listeners crazy, and likely blow up tweeters much sooner.
It's the woofers that steal power, so they are the most critical for efficiancy issues. Folded horn bass cabs magnify the output for a givin input wattage. While ported cabs with lots of back preassure sound fine, and are smaller, but take a lot more power to run.[This message was edited by David L. Donald on 12 March 2003 at 11:45 AM.]

Chris DeBarge · Post by **Chris DeBarge** » 13 Mar 2003 5:32 am

Sure, use the D130's. Get an old plan for a folded horn, you're off to the races. Unfortunately, like the Altec, those cabinets can get quite unwieldy.

There are many books on designing a speaker cabinet, why not build your own? You could then give it a vintage look.

Jussi Huhtakangas · Post by **Jussi Huhtakangas** » 13 Mar 2003 5:56 am

Chris, my buddy, that's exactly the plan now. Just scored a pair of Altec 418's (15" )for 200 bucks, now gotta find a handyman to build the cabinets

David L. Donald · Post by **David L. Donald** » 13 Mar 2003 6:56 am

Cool! keep us informed how it goes.