Hi All,
I'm helping a friend who wants to make use of an old cabinet with speakers, tuner, and built in phono -- you know these old things you see sometimes that open from the top to access the record player, etc. . . ? Not interested in an original restore, but rather an easy way to add a bluetooth and line input, etc. . . I was thinking a little class D amp, a raspberry pi, and a selector switch. The speakers currently work, and I'm trying to figure out if I could drive them with a reg amp? I've worked on tube gear before, and comfortable with soldering and whatnot, but wasn't sure if these speakers need something esoteric to drive them. We'd like to replace the old amp in there.
Each side has two little tweeters and this woofer. Any idea if these could be driven by a regular amplifier? I've one messed with full range speakers before, but I assume the capacitor there functions as a crossover for the tweeters?
Any help appreciated, and apologies if there is a better forum for this.
I'm helping a friend who wants to make use of an old cabinet with speakers, tuner, and built in phono -- you know these old things you see sometimes that open from the top to access the record player, etc. . . ? Not interested in an original restore, but rather an easy way to add a bluetooth and line input, etc. . . I was thinking a little class D amp, a raspberry pi, and a selector switch. The speakers currently work, and I'm trying to figure out if I could drive them with a reg amp? I've worked on tube gear before, and comfortable with soldering and whatnot, but wasn't sure if these speakers need something esoteric to drive them. We'd like to replace the old amp in there.
Each side has two little tweeters and this woofer. Any idea if these could be driven by a regular amplifier? I've one messed with full range speakers before, but I assume the capacitor there functions as a crossover for the tweeters?
Any help appreciated, and apologies if there is a better forum for this.
What's the original amp, and does it have a 16ohm output? I see the tweeters are 16 ohms each. A class D amp will most likely have a 4 ohm output impedance.
jeff
The two 16 ohm tweeters are in parallel giving an effective load of 8 ohm. I would presume the woofer to be 8 ohm. The capacitor acts as a filter, blocking the low frequencies and allowing only the high frequencies to pass to the tweeters.
I see no reason why this combination can not be driven by an 8 ohm capable amplifier.
It may be a good idea to replace the capacitor with a modern non-polar (bipolar) equivalent.
A class D amp will almost certainly have an output impedance near zero. But they, as a general rule, are quite 4Ω capable.
dave
Maybe I am mixed up was thinking of using an old Topping TP20 as an amp, which is technically class T? I thought it was class D. It seems to drive 8ohm fine.
It is small, replace with a poly. Those tweeters are not that good. it probably sounds better without them connected.
dave
Depending on what inputs/functionality you want, you may get by with an all-in-one unit like this
https://www.parts-express.com/Lepai...r-FM-Media-with-Power-Sup-310-3020?quantity=1
I’ve done dozens of these, some built from scratch, some vintage. If you don’t wan’t to keep the original electronics, then a Claas-D amp module will do fine. You can find them with Bluetooth onboard, but beware of the cheap ones on eBay, all I bought were very noisy.
If it’s feasible for you order from Parts Express in the US, they have a good selection.
If it’s feasible for you order from Parts Express in the US, they have a good selection.
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Hey Pano,
Would love to see any pics / hear ideas you have for these things. Helping a friend with this one -- no interest in keeping the original electronics -- just want something decent, that works. But trying to think of a nice way incorporate the record player -- do you look for drop in replacements generally? For a Class-D amp, thought we might try and mount it from the bottom so only the controls show through the top panel. . . More about making the thing useful than staying original.
Would love to see any pics / hear ideas you have for these things. Helping a friend with this one -- no interest in keeping the original electronics -- just want something decent, that works. But trying to think of a nice way incorporate the record player -- do you look for drop in replacements generally? For a Class-D amp, thought we might try and mount it from the bottom so only the controls show through the top panel. . . More about making the thing useful than staying original.