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Admiral AM/FM Stereo Multiplex Console

Recapped the amp and speaker crossovers today. Can't say it sounds any better, but haven't done any critical listening. Still need to recap the preamp/tuner......figured out how to get it out of the cabinet today.

It appears to me the weak link in the sound of this console has to be the speakers. Am pretty sure the two pairs of tweeters are cheap paper cones. The woofers might be OK sounding, but they are mounted on an open baffle, which probably severely limits how good they can sound.

Any cheap upgrade ideas in the speaker driver department?
 
I pulled the preamp/tuner from the console today to see what caps in it need to be replaced. It only has two tubular type caps: a 10 uF 300 VDC electrolytic and a nonpolar .022 uF 600 VDC.

I have the .022 cap on hand. But the closest I have to the 10 uF cap is a 20 uF 500 VDC Sprague Atom. The negative side of this cap is grounded to the chassis. My guess is the other side of the cap is connected to the power supply from the amp (at least the wire is coming from the amp umbilical plug). Would it be OK to go up +10 uF in this application to 20 uF?

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Up-sizing the cap worked in this instance. Just finished the refurbishment on this console.

Can't say it really sounds any different or better after being recapped and putting a 12AU7 in the slot where a 12AU7 goes (instead of the 12AT7 that was in it as found). As I said earlier, the speakers definitely seem to be the limiting factor. Need to try some external speakers to see if it sounds better.
 
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BmWr75 said:
Hey Guys,

I picked this up today at the Habitat for Humanity store for $10. The kid there says it plays and sounds good. I bought it cause it has tubes inside. Here's some pictures before any clean up. I've not tried it yet.

When I got it home was pissed......no CD/iPod input. :D

Scott
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Those Habitat stores are interesting places.Just went to the one near me,and picked up the Philco in my sig.It was $20.00.They had a Zenith Allegro for $25.00. :thumbsdn:The store I went to,is half of a converted roller rink.They have a small thrift store section,and the rest is all used building materials,plumbing stuff,etc.
 
No problem with 10uf over (might even be to its advantage). Any chance the woofers are out of phase?
 
Speakers a limiting factor, been there done that, lol. I had a thread on here about the same thing. I found it was weird my low end magnasonic open back mono console sounded better than the near top o the line stereo imperial with 2 15" woofers and horns. Long story short is you will never get amazing bass from these consoles because of the turntables and feedback. And im not talking about window rattling bass, but crisp tight firm bass, something that shapes it up nicely.

I took the old woofer out and hooked it to a signal generator, 100hz, the cone is movin like crazy, but its hardly makin any noise. It didnt really wanna produce those freq's that make the bass sound good. So I swapped it out with a new 15" woofer, that wasnt nearly efficient enough for the 15 watt amp, but a new woofer basically fixed the problems. My suggestion is to find the most efficient woofer you can get and start there. 95db or higher if you can. You have an EL84 amp, a little more stout than the PP6L6's driving the woofers in my imperial.

Horns tho are all in the eye of the beholder. Having gain control over them separately would be good if your gonna mix and match. The Bi amp in my maggie has a gain control for the horns, (its a stereo bi amp, PP woofers 15watts, SE horns, 5 watts, all 6L6) You can get em, and i think the maggie horns sound really sweet and require very little power, would be a nice combo with a good efficient woofer.

Sealing the speaker cabinet may help also, and treating the inside and porting....but your main issue is gonna start with the quality of the speaks
Mark
 
I snipped the speaker wire leads today and wired up some eWave variants to the console amp today. Sounded a little better, but not great. This thing will never be Hi-Fi sounding in my opinion. So, rewired the original cabinet drivers, yanked the Amperex EL84s and replaced them with some cheaper tubes, and buttoned her back up.

She looks pretty and functions perfectly, but Hi-Fi she ain't. The wife and I need to decide whether to keep it as a decorator piece and pass it on to someone looking for a 1960s chic console.
 
The top refinished nicely. Looks like oak I guess, not fine grained like walnut. But, I'm not a woodworker, so it could be any kind of wood. :scratch2:

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My first hifi purchase was a solid state Admiral AM/FM receiver with Admiral speakers in an "acoustic labrynth". I bought it with paper route money about 1968 or '69.
I'd wanted to go to tech hifi, but my dad convinced me that his friend had a good sounding unit at his store.
Actually, it sounded quite good, with the caveat that the phono input only worked for a ceramic cartridge type turntable.
I used it for a couple of years and then upgraded. My dad kept the receiver, but I'd taken apart a speaker to learn what an acoustic labrynth was and how it worked. I still have drawings I must have done as a project in my drafting class.
Fast forward 40 years and I found the receiver under my dad's bed.
Within a few months I'd found a replacement pair of the original Admiral acoustic labrynth coaxial speakers on my local craigslist and I set it up as a garage system.
Actually, it still is pretty darned good sounding and has always been absolutely reliable.

Yes, those tubes look very amperex'ish.
 
BmWr75 said:
The top refinished nicely. Looks like oak I guess, not fine grained like walnut. But, I'm not a woodworker, so it could be any kind of wood. :scratch2:
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It's a shame something that looks so nice can't sound that way... :no:

Brian
 
I have an old Admiral Stereo demo record and it says they use dual channel amps? 2 mono's?
 

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Do you have an outboard preamp or an integrated or receiver set up so you could try the pre part of the receiver with the amp?
 
Does the Pope have some funny looking hats??!!

Yes I do.....but that is way down the To Do list at this time. Thanks for recommending it though, I will check out just the amp sometime.
 
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admiral wiring diagrams

does any know where to get the schematic diagrams of the admiral stereo that you guy are talking about would you? I want to redo all the components and maybe do some mods to it
 
A27 said:
"..no CD/iPod input"

I bet you were really let down when it didn't have an "f" for facebook button.

I love it when people call it an ipod plug/jack. I do correct them on the spot with "It's an 1/8" mini plug/jack." But oh! now it works with an ipod they are double the price they used to be.
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you joke about not having a ipod hook up i made i hook up for it sounds great nothing like hooking up new music with tube sound ahhhhhhh
 
@tom bavis said in an earlier post "Amp and tuner schematic are in Sams folder 666-1".
 
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