Altec Valencia 846u Restore

[rshep]

Here’s a thread covering “How I Spent My Summer” restoring my Valencia 846u speakers.

They were purchased from a Craigslist ad, I drove from Phoenix to Tucson to pick them up. It was a fun outting, I brought my daughters and older daughter’s boyfriend with me. We got to have Eegee’s for lunch. If you ever visit Tucson, you have to try Eegee's.

Back to the speakers. One was fully functional, the other had a bad diaphram. I ordered the “AL-26420XX Altec Lansing Factory Speaker Diaphragm, 34647, 26420XX” from Simply Speakers. The diaphragm install wasn’t too bad, just like upgrading the tweeter diaphragms in my Klipsch Forte II’s.

Here’s a photo of the driver opened up. This is the original diaphragm. I made new jumpers because the replacement diaphragm uses push-on connectors instead of attachment screws.


I got them back together and set them up for a couple of weeks in the family room. They sounded really nice with my Dynaco SCA35. I thought they were a big step up from my Forte II’s. Altec midrange clarity might not be everyone’s cup of tea but I love all the detail and how vocals just stand out. (stay tuned, more to come)

 

[Marine0811]

Those are sweet!

 

[WaynerN]

Aren't they suppose to have risers on the bottom?

 

[marantzfan]

I'd like to see what you did with them. I remember seeing them on CL and had to fight the urge to pick them up. I love Altec speakers.

 

[rshep]

Aren't they suppose to have risers on the bottom?

At one time they sure did. By the time I bought them one was somewhat intact and the other side was destroyed. I ended up building 9" bases for them, I'll have some pictures up once I get to that part of the restore.

 

[rshep]

One of my requirements of the voicing for my stereo systems is being able to play in the 90db to 95db peak SPL without harshness. I don’t usually listen that loud but it seems whenever I get a system dialed in that’s the test for me. With the original cross-overs I did experience some stridency in the midrange.

Doing some research and what I learned is that cross over changes were a big help for Valencia’s. The late Zilch stated that either a new Model 19 crossover design, active crossover or adding a attenuator network that would allow tapering of the midrange from the horn without affecting the higher frequencies. I decided to recap the original crossovers and build the 30923 “attenuator equalizer network” between the stock crossover horn output and the horn. My understanding is that the attenuator was added to the Model 19 design and that helped make them the standout speakers that they are.

Here are some before and after photos of the crossovers

One of the new 30923 networks that go between the stock network horn output and the horn itself.

 

[rshep]

I have a cool little Chinese part checker that measures capacitance and ESR among other things. The kit cost about $15 with shipping from China.

Here are some typical before and after measurements. This was the 8uf cap.


The old cap measured low at 7.548 uf with an ESR of 2.0 ohms


The new cap measured 7.980 uf with an ESR of only .45 ohms

 

[rshep]

I'd like to see what you did with them. I remember seeing them on CL and had to fight the urge to pick them up. I love Altec speakers.

I sure will, I have lots of pictures and will share some of my learnings and then enjoy hearing feedback from folks that are more learned than me.

I'm rather smitten with my Valencia's. I can't imagine what it would be like to have a pair of Model 19's in the music room.

 

[alteclipsch]

Aren't they suppose to have risers on the bottom?

I have a friend who has the 846U and his pair has no risers. He had a welder friend do up a pair of 1" steel channel risers about a foot tall. Great speakers!

 

[sqlsavior]

Congratulations!

I'll bet they sound superb.

Now, find a pair of wrought-iron gates, for grills!

 

[rshep]

Here's my rig for testing the cross-overs without the speakers. I ran pink noise into my Hafler DH200 and connected 8 ohm dummy loads to the woofer and horn outputs.

 

[rshep]

Using Spectrum Analyzer software I checked how the “attenuator equalizer network” performed and verified the both pairs of cross-overs were working equally.

This photo is with the attenuator set fully clockwise with no change between the input and output.


Here's the attenuator in action, cutting the midrange down without affect the upper frequencies.

 

[gdmoore28]

Love what you are doing with the Valencias, Shep. This thread will be a good reference to others who want to do the same crossover design.

I went roughly in the same direction as you with my Altec build, which is essentially finished (there is still some testing and minor adjustments to be made). My special interest in your thread is the crossover. I skipped the stock Altec crossover and built my own, instead. Mine is a simple LR Second Order network (Crossover 800Hz; 12db slope; etc.)

Like you, I installed the Altec 30923 network with the adjustable mid range controller. The Altec "Equalization/Attenuation Network" is just the bee's knees, isn't it? I found that - in my personal preferences - incorporating the adjustable midrange attenuation feature is unnecessary. Any adjustments I've tried so far has not yielded any improvement above and beyond the 30923's alone. At this point, I've taken the adjustable L-pad out of the circuit. Eventually I'll hook it back in place simply because it's a nice feature that I might change my mind about. We'll see.

I very much like the direction you took in building the 30923 network on a separate board. I built mine on the same board as the crossover. I can't locate my crossover picture, but maybe you can see it sufficiently here:



You can see my project here: http://audiokarma.org/forums/index.php?threads/altec-606-inspired-build-using-a-7-components.766911/

Anyway, looking forward to seeing and reading much more about your Valencia adventures!

GeeDeeEmm

 

[rshep]

The cabinets were in pretty rough shape. The worst was a 9” square area towards the rear bottom that was water damaged. A really poor patch was attempted, but the particle board was swollen and it would have never smoothed out correctly. There really weren’t any edges that didn't have either dents or strips of veneer missing.

 

[rshep]

There were spider webs in the cabinets. A few years back I installed some equipment racks at work that had webs on them. We brushed them off but about a month later we had spiders all over the place. Needless to say, I sprayed some insecticide on the insides of the speaker cabinets and let them vent out for a week before continuing. There was also some mildew smell inside, I sprayed diluted bleach all other the interior. After the bleach smell dissipated the mildew odor was gone.

 

[rshep]

You can see my project here: http://audiokarma.org/forums/index.php?threads/altec-606-inspired-build-using-a-7-components.766911/

Anyway, looking forward to seeing and reading much more about your Valencia adventures!

GeeDeeEmm

Thanks GeeDeeEmm, I went to check out your project thread and realized that I had already checked it out when I was researching my speakers back in June. You have some really good information and details in your postings. I especially liked the repurposed kitchen corner cabinets.

 

[rshep]

Here's the schematic for the 30923 network. I don't recall if I got this from AK, or the Altec Users board or Altec Lansing Heritage website.

 

[rshep]

I also have some better captures from the spectrum analyzer showing the action of the 30923 network connected after the N800k network. All are pink noise into a 8 ohm dummy load.

Mid set to full attenuation:

Mid set to min attenuation (same as bypassing the 30923 network):


Here's what part of the pink noise makes it to the woofer:

 

[gdmoore28]

RShep-

Can't tell you how much I appreciate the graphs and schematics you've assembled for us here. I think, outside of Zilch's work, this is the first time I've seen this information all together in one post. It's so interesting to finally be able to see what I've been hearing by incorporating the 30923 network.

I think it goes without saying that none of us will get mad if you post any and all of your findings. This is all very helpful to those of us without analysing gear.

GeeDeeEmm

 

[drbiggles]

Hey man,

I stumbled into your thread here for fun, to see what the scoop is. I was just planning on lurking through it and going on my merry way. But after seeing the condition of your cabinets, it brought me back to my Altec Valencia restoration. Our cabinets were very similar in condition. Yours look like there's more missing veneer than mine had, but mine had more missing/water damaged particle board. There was about 30% of the backs on mine that had to have the particle board restored, and entirely missing corners. In my thread, it was suggested more than a few times to build new cabinets, or replace with new veneer. It took a lot of time and effort, but I got them all back together. Afterwards, I wasn't able to find the vast repairs to show the new owner. I wish upon you great luck in your efforts!

Biggles