NOS Altec 755E: Q: CABINET / AMP / TWEETER?

Hi ,

This is my first post on the forum.

I am about to by a pair of NOS : Altec Lansing 755E´s
I have some questions regarding these drivers:

I am planning on building a DIY version of the Altec 618 cabinet—very the same as first attached picture.

THE 618 CABINET
1. Pine plywood is the correct material to use? and not birch….

5/8inch ( 15mm ) on front baffle.
1/2inch ( 9mm ) on all other sides of the cabinet.

“ [* Edit: Yep same as Altec " The thickness of the front baffle is a sound board thickness all 15mm, otherwise it is 9mm It has become the preferred structure."-- from Stereo Sound WSI 618C writeup] “ - from junkyardjukebox

2. How much stuffing / fill do I need / and what kind of material should I use?

AMPLIFER MATCHING
1. I have a Gainclone LM3875 kit—some say it has an equal sound signature as 300B SET amplifiers. With a 92dB sensitivity on the 755E - any inputs?

2. Other well known amp alternatives for the 755E?

SPEAKER STANDS / HEIGHT
1. How high should I rase the 618 cabinet?

TWEETER ( if even needed )
I have a pair of DECCA Super Tweeters ( ribbon ) :
Frequency range: 7KHz-30KHz
Crossover: 7KHz
Efficiency : 88db at 4W at 1meter

1. Is this a Plug & Play?

LAST QUESTION:
Difference in Resistance : a 0.3ohm difference around 6.8ohm on these NOS drivers— this should not be anything to worry about?

PS:
How does these drivers sound? very interested to hear your opinion on these drivers.

Attachment 82137Attachment 82138Attachment 82139


REFERANCES
1. Vintage pine 618 cabinet: Attached
2. JE LABS 618 drawing: Attached
3. Regarding thickness of the 618 cabinet: http://junkyardjukebox.blogspot.com/...nside-box.html
4. Spec sheet The Decca SUPER TWEETER: Attached

:) Welcome to the forum. My first visits here were similar to yours in that I was also looking for information about an 8" full range driver, only my focus was the JBL LE8T to be used for TV sound with a CRT TV, and that meant quality drivers with Alnico magnets and their very effective magnetic return paths. My knowledge of the Altec 755 is very old and part of the evidence of a misspent youth, misspent foraging in thrift stores, flea markets and garage sales for interesting audio artifacts, a process that turned up one pair of AR-1's, which used them as a tweeter, two pairs of 755a's and one pair of the e's. I listened to the a's and liked them, but I had little interest in full range drivers at that time and passed them on. I don't actually recall listening to the e's.

You may have read, as I did, that the cone in these drivers was designed with utmost midrange clarity in mind for use in communications on board ship during The War. Urban legend possibly, I don't know. There is a photo in Badmaieff of one being used for music in monaural days. In any case I believe it is for their midrange, and rarity, they are now valued at collector fever prices.

Oddly, I am not aware of any current maker using a replication of that cone.

As is the case with many full range drivers of that size, they in truth need help in the highs and lows for, well, highs and lows.

What is the photo included for? Your's? The seller's?

What happened to me at Lansing Heritage was that I was soon distracted by large heavy-coned woofers and big four-way blue-faced monitors driven by hundreds of solid state what's, so be careful! :p

Hi ,

Thanks for the input. I have previously owned a pair of Altec 604E´s; of course not as big as the blue faced JBL units you are talking about…. I´m hoping to land my hifi quest with the Altec 755E´s. It truly looks like we are going in opposite directions…. ;-)

I am not sure if I understand your one question; about the attached jpg files; they were found on net by me and only ment to illustrate my opening questions for this thread.

Anyways; I am aware that the 755 driver has its limitations; but that is also a fact about the size of my living room. as a followup : listening to alot of jazz , small assembles classical music, so hope this driver will do the job :-)

Did you see this older thread?
http://www.audioheritage.org/vbullet...g-with-tweeter
I'd try to find something nicer than pine. And thicker.

Attachment 82141

Yes .

I have seen this post; probably also the same reason why I´m dropping jazz as one of my faves…

Most of the different tweeters mentioned are unknown to me and I have the Deccas on hand, I have little knowledge about integrating tweeters, but know my Decca´s play well and matches good with my Quad ESL 57´s, but unsure what to tweak , if anything, in implementing them with the Altec 755E´s.

While we´re mentioning threads; I have also read this one: http://www.audioheritage.org/vbullet...-755e-Speakers ; both of these two threads are by first time posters, like me, here at the heritage forum.

I do not know; but with no better results here response wise, I guess I´ll figure this one out on my own. A bit sad, mostly because I am very eager about my newly acquired drivers and was hoping for better results, to me it looks like they have a large fan crowd; several blogs mentions these drivers as very interesting drivers.

They are not the biggest / nor the coolest ( referring to blue faced things here… ) but if they are as good as I am hoping for, I would like to get a hold of a pair of 755C´s, the 755A´s are way out of my league price wise … same goes for the alnico 755A reissue from LM Audio.

One last input; attached png; all panels will be 9mm pine plywood; all dimensions in mm, based on the JE labs sketch earlier attached. Two of these units will fit fine on one standard plywood sheet ( 1220x2440mm )

May be you get more help on The Altec User's Board

Thank you! :-)