The Vintage Altec Codex

[junker]

Dear current and prospective Altec speaker owners:

In purchasing a pair of vintage Altec Flamencos (848A) I have been rewarded by so much great sound reproduction, and excellent integration with Shindo gear and low-watt tube applications due to their ~100 dB sensitivity and 16 ohm load. During the past 18 months that I've owned these speakers I've also become accustomed to their limitations and trade-offs, and have committed a great deal of time, effort, and money in upgrading them in numerous ways that stay true to the original nature of the design...what I would call OEM+. And trust me there is a lot to talk about here. Also, I've come across so much blatantly wrong information and dogma out there that I feel I needed to relay some of what I've learned. So, here we are. Please feel free to share your experiences and knowledge and perhaps we can all gain something from the discourse. Thanks!

-Josh


Linked to previous thead here: http://www.audioaficionado.org/723211-post25.html

Originally Posted by junker

Yeah definitely consider this... Tables are a game changer! I'm going to kick-off another thread on vintage Altec speakers where we can all have a dialogue regarding our vintage Altecs. I've considered them my main hobby project for about 18 months and have another $2-3k into them for what I would consider OEM+ upgrades and have learned a tremendous amount that I can share (some of the secrets!). At the last Pitch Perfect event I went to I was surprised at how many Shindo owners have gone through great lengths to use these as starter speakers for moving into the Shindo, vintage, SET direction. And yet there is so much dogma out there that reads from some limited Art Dudley comments - even he alluded to L-R balance issues and perhaps building crossovers. I'm going to go on the record for saying that the magic of these speakers is inherently due to the drivers. It is absolutely not the crossovers, the cabinet materials, the insulation, or the wire type. These are not Shindo. Historically, Altec primarily made drivers for both professional and custom installations and sold the drivers and crossovers as individual components. Then, at some point (mid-60's) they seemed to expand into the residential market. Both the crossovers and cabinets have numerous cost-cutting measures and, in fact, the cabinets were outsourced. Also, please remember the crossovers are in a welded closed aluminum can and are potted in tar. I've bought an extra set and extricated the components to confirm the plans I've used are correct. Trust me you do not want to do this... Electrolytic caps do dry out, and values do drift. L-Pads will never be as good as a fixed R value. And for god's sake there is nothing ideal about having both ferrite cored inductors sitting next to each other at the bottom of that infernal can - that is a big no-no as inductors crosstalk due their magnetic B fields coupling. And if you want to ever replace the captive 50 year old tinned 20 gauge Belden wire you effectively need to replace the crossover. And if you replace the crossover you effectively should either replace the backs (MDF!), or leave the stock crossover as a vestigial appendage occupying valuable cabinet volume that was used to calculate the port size. No, there is a cascade that you start to get into when you go down this path but there are clear and dramatic improvements along the way to be sure. There is a lot of potential left on the table in the stock enclosures.

Definitely be sure to read over this ALTEC loudspeaker design document from 1968 just so you can understand how these very special drivers are intended to be used by the manufacturer. This also includes the enclosure schematics for the A7, Valencia, and Flamenco. =)

-Josh


http://www.greatplainsaudio.com/vint...sures_1968.pdf