New Heathkit AS101 owner - First post.

**zelgall** · December 6th, 2012, 03:10 PM

In paralel but you'd still need a cap on the output. Don't OTL's run as cathode followers?

GM · December 6th, 2012, 06:03 PM

Originally Posted by alancohen

Really???

What? The price? Try finding those grills by themselves at any price.

GM

**Altec Best** · December 7th, 2012, 02:39 PM

Originally Posted by alancohen

I'd love to listen to the 23744s, but maybe like Earl mentioned, the 34647s might give me a more realistic sound of what I'd have to expect from a new set.

They aren't that much different to my ears Alan.. To me anyway. I just prefer them a little more but they are very close in performance IMHO.. I have 34647's but they are in new refurbished drivers that I haven't used yet,so i don't have any lose ones laying around.I wouldn't worry about them as long as you use some protection for the high pass and keep the volume at reasonable levels they should be fine..I will test them before hand.I have lots of them so I'm not worried about replacing them anymore..I still have brand new 802G's that are still in the boxes with those 23744's I will be fine... It's your call if interested..

**Altec Best** · December 7th, 2012, 02:59 PM

Originally Posted by alancohen

Really???

Vintage 1969 Altec 846A Valencia Speaker Cabinet Pair w 416 Z 806A 811B N 800 | eBay

That is a lot of money for Valencia's, the most I have ever seen them go for.

**alancohen** · December 9th, 2012, 10:50 AM

So, I got one 30923 HF compensation circuit built. I'm working on the second. So far so good with the sound. It's hard to tell with both speakers going and not knowing what is supposed to be in each channel. But I'm hearing a nice rat-ta-tat-tat off a high hat in the right speaker and not so much in the left. I want to measure both, but I need to wait till my new mic shows up. Maybe I'll try the Samson for yucks.

**alancohen** · December 9th, 2012, 11:38 AM

So the blue is without the HF compensation circuit, the green is with... It doesn't seemed to have helped.

But to tell you the truth, I'm more concerned with the lack of bass response. Where the heck is 50-500Hz? Is this normal, or are my 416As are tired?

**Earl K** · December 9th, 2012, 01:33 PM

Originally Posted by alancohen

So the blue is without the HF compensation circuit, the green is with... It doesn't seemed to have helped.

But to tell you the truth, I'm more concerned with the lack of bass response. Where the heck is 50-500Hz? Is this normal, or are my 416As are tired?

(i) I can assure you, that ( when you first listened to your speakers 4 weeks ago ) if they had even remotely resembled this latest test trace , you would have concluded that your new speakers had blown woofers and been asking the forum for help on how to fix them .
- Since you've never ( till now ) mentioned such a total lack of woofer action ( from your previous listening sessions ) , the logical assumption is that your measurement technique simply isn't allowing the woofer to be picked up into the test mic ( or something similar ) .

(ii) It's always possible that this new "T-Pad" is miswired into the circuit somehow ( maybe the original variable Lpad was wired backwards ) . I'd suggest bypassing that ( stock ) variable pad and trying again .

**alancohen** · December 9th, 2012, 01:42 PM

Will do, Earl. I keep it all the way up anyway.

As far the the LF response, the curve seems similar to the ones you posted a couple of pages ago:

Not much below 500Hz there either.

**Earl K** · December 9th, 2012, 01:51 PM

Not much below 500Hz there either.

Yes but, my measurement was taken of just the horn ( the woofer was out of circuit / & off ) .

- Where is your test mic situated ?

- For measurements where you want to capture both woofer & horn information , you need to be at least 3 ft away, with the mic centered midway between the horn & the top of woofer .

**Altec Best** · December 9th, 2012, 02:12 PM

Originally Posted by alancohen

So, I got one 30923 HF compensation circuit built. I'm working on the second. So far so good with the sound. It's hard to tell with both speakers going and not knowing what is supposed to be in each channel. But I'm hearing a nice rat-ta-tat-tat off a high hat in the right speaker and not so much in the left. I want to measure both, but I need to wait till my new mic shows up. Maybe I'll try the Samson for yucks.

Looking good.Making some progress.. Here's a photo of one of a pair that I have of an original 30923 that I got with a pair of 1285-8B's.

The 1285-8B's are adjustable from (500-800-1200) Hz which is nice for trying different setups.

Here's a photo of the original 30923/30904's that ArtJ did for the Altec board.. I think Earl posted the schematic of it already but the photos were missing.