Metropoulos Forum

Hi all. Firstly, merry Xmass to everyone here.
Ok, not having an amp project going lately I've taken to building stomp boxes for a few friends, hard wired tube screamers, "starved plate" 12AX7 distortion pedals, that sort of thing. I've always liked the talkbox effect, so rather than pay the rediculous price they're asking for a Dunlop Heil here in Oz I thought I'd have a crack at making one. Soo,as the reccomended EV1824M driver is no longer made, I ordered a cheap JBL Selenium D250-X GW mid/high driver to do some experimenting. From reading threads here I found that the Heil, & other home built's use a 15 or 16uf/100V non polarised cap in series with the driver to give a 6db/octave roll off at around 1200 or 1300hz, but that people would like a little better low frequency response than this gives. The D250-X GW is rated at 100W with 12db/octave at 400hz & 200W with 12db/octave at 500hz (which is reccomended minimum). My thoughts (& this is something I'd like input on) is to put a 22uf in series with the driver & put a 2.7mh air cored inductor in parallel with the driver to gives 12db/octave roll off at around 650hz. The only thing is that I've not heard of anyone using an inductor in a talkbox b4, so any input on this would be very much appreciated.
The other thing I wish to ask is can anyone tell me the I D (internal diameter) of the hose used on the Heil talkboxes? As I can get an adapter turned for this I figure I may as well get it made to fit the same size hose as the originals. Thanks in advance, & Merry Xmass. Cheers

I have an old 77' or 78' Dean Markley 100 watt "grey" talkbox. Dean Markley also made a 50 watt, and a 200 watt talkbox versions. These three talk box models were specifically designed to be used with the Marshall 50 watt, 100 watt, and 200 watt amps. The 50 watt utilized a JBL horn driver, the 100 watt utilized a Altec-Lansing horn driver, and the 200 watt utilized a EV horn driver. Of all these three models, Mr. Dean Markley preferred the Altec-Lansing horn driver the best (he tried to buy mine from me) just a FWIW.

Hi Lefty Lou, thanks for the answer & info. Its not surprising that the altec-lansing was the better sounding of the 3. Interesting that he wanted to buy it off u. I'll use this JBL driver to experiment with filters with, then maybe buy a better quality driver later. I've found after a little more searching that the Heil used a tube measuring 5/8" OD x 1/2" ID x 1/16" wall thickness, but other units use a smaller diameter tube so I'll get 2 different sized adapters turned by my friend. Thanks again. Cheers

ivan H wrote:Hi Lefty Lou, thanks for the answer & info. Its not surprising that the altec-lansing was the better sounding of the 3. Interesting that he wanted to buy it off u. I'll use this JBL driver to experiment with filters with, then maybe buy a better quality driver later. I've found after a little more searching that the Heil used a tube measuring 5/8" OD x 1/2" ID x 1/16" wall thickness, but other units use a smaller diameter tube so I'll get 2 different sized adapters turned by my friend. Thanks again. Cheers

Lefty Lou wrote:The phone conversation was in the 80's when you could call a company like Dean Markley and actually get ahold of a CEO of the company personally. Indeed rare these days. Altec Lansing was located in Okc., Ok. for awhile as an old friend of mine worked there for several years. Occasionally Altec would have in house auctions that employees were allowed to participate in. I ended up getting a 400 watt Altec power amp for $41 through my buddy who worked at Altec, as well as NOS tubes such as the Amperex "Bugle Boy" EL34/6CA7 tubes and other miscellaneous NOS 12AX7 types. I had several Altec horn drivers from this friend, you and Dean Markley are both correct they are excellent drivers.