viral projects, sort of

music soothes the savage beast
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Speaking of fun, i have decided to put together garage system. Mosty from leftover unused stuff.
I had nice pair of Blaupunkt 12" woofers, which survived lots of abuse in various reused boxes, so i made them into dedicated sub-woofers. I got two ikea tables, $7.99 each and glued sides from plywood. There is no bottom, since this is cheap project.
Top midbass-tweeter will be whatever i have left, and i got a lot. I will keep replacing the top, have fun voicing the crossovers.
System is biamped using simple active crossover, jvc superA power amp for top and car stereo amp for woofers.
 

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music soothes the savage beast
Joined 2004
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Right now you see line array of little aura fr drivers augmented with forster supertweeter. Line array was actually reworked to MmtmM 2.5 way. Still work in progress.

Next speakers to test are from left:
A) 3way hivi planar plus dayton soft domes mtm with two daytom 6" mids on sides. Very good sounding speakers, definitely best in this bunch. I used them for HT till i got better. Not really garage stuff, wasted here, just for comparison.
B) big monsoon planars, mid and tweeter, plus two cheap woofers as midbasses. Not a bad sounding speakers, but much lower efficiency.
C) these are 2way tops, which i reworked few times, and are definitely better than monsoon. I used to have those aura bending wave tweeters on flat plane, but i did not like beaming. There was different offaxis response between midbases and line of tweeters. Curving the tweeters solved the problem. Very pleased with sound. Crossover is one cap only.
D) small monsoons, array of aura fr drivers plus monsoon tweeters. Again, one cap wonder crossover, amazing coherency, since aura are used as is and they rolloff at 10kHz where monsoons take over. I use these speakers a lot.
E) speakers in back, faitalpro 6fe200 with eminence apt-80 supertweeter. Work in progress, as crossover needs some fine tuning. Apt-80 has some bumps at ~5kHz which needs taming down. Very efficient, open back, but i hear some low mid resonance, will have to drill some holes in sides.
 

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music soothes the savage beast
Joined 2004
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I never revealed the secret!
Just kidding, its no secret.
You spread the gorilla glue on your surface, wood or foam board, you can spread in lines, or use spatula to make glass like surface, resulting in slightly different patern. Just lines for toad skin. Then you take small sponge or foam, and you gently tap the surface. Different foams create different size blisters.
You never know what you get.

ob1.jpg
 
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music soothes the savage beast
Joined 2004
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Here is another toad skin example for scotty gee...i had this small bookshelf based on aurum cantus ac130f1 with beston planar, one cap wonder, in foam board enclosure, sounding so great that i thought it deserves better.

I bought ikea bookcase, and added front and back from plywood. Here is before painting, just dried gorilla glue, during painting, and almost finished. I will give it one more black paint.

Great as computer speaker, or satelites with sub for more serious listening.
 

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music soothes the savage beast
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Just had some time, so i made extensive listening comparison of two preamps and two amps. In every case, eq was adjusted for flat fr response in listening chair.

Compared wolverine to dartzeel. Darzeel is ebay clone, no original. I got two wolverines. In every case i prefered sound of wolverine.
The main difference is in clarity and smoothness. I know, you can not define that exactly, but i do not care. Both are classAB, but wolverine sounds more like great classA, smooth.

Next i compared ba3fa with scg. I built both of each. I measured all four. Both ba3fa had lower distortion than two scg pre. That's expected. I only compared one ba3fa with one scg (the best in both) with wolverine.
I preffered scg, for much more musical presentation. Ba3fa sounds a little dry to me.

Just finished bunch of Hamptone pre, should be fun.

Posibilities are infinite.
 
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music soothes the savage beast
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When i was cleaning attic, i found an old Magnavox se amp, 6eu7/el84. I have rebuilt it long time ago with new power supply. So i brought it down and tested it in the main system. Agains wolverine :). Yes, it had no chance. Sound is pleasant, polite, romantic, but lacks high fr clarity. Highs are too soft, i guess thats what second harmonic does.
It works great as headphone amp, with small resistor l-pad on output. But i have many headphone amps already.
 
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I've been building these for too long. I finally made some time and got my buddy over here to help.

By the book, right out of the box it's almost a bull's eye. I'm going to put stuffing in and listen and measure and trim the port to length (or not).

I was surprised by the clarity and also by the bass output. From here it can only get better.
 

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music soothes the savage beast
Joined 2004
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Found old Sparta riaa preamp. Put together simple inverse riaa passive circuit so i can measure it. I always liked its sound, perhaps i will use it again. It was completely recaped long time ago. No schematics.
Measured impressively low thd 0.022%. Its full germanium riaa pre with transformers on the output.
Now i need to make good power supply, it has some 60Hz hum.

Funny thing is you have to use positive supply as 'ground'.
 

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When i was cleaning attic, i found an old Magnavox se amp, 6eu7/el84. I have rebuilt it long time ago with new power supply. So i brought it down and tested it in the main system. Agains wolverine :). Yes, it had no chance. Sound is pleasant, polite, romantic, but lacks high fr clarity. Highs are too soft, i guess thats what second harmonic does.
It works great as headphone amp, with small resistor l-pad on output. But i have many headphone amps already.

Repurpose into small guitar amp? It's the rising impedance of guitar speakers, and the midrange spikes, that give the "bite." A stereo amp can drive two speakers easy, even large guitar speakers.

You can add some presence by putting a network on the input. While this is sketchy for hi fi, it seems perfectly kosher for a guitar amp.
At least try some different speakers and see how it sounds. Murkiness might go away with different speakers. Tube amps have higher output impedance, and in some amps the impedance varies with frequency, so you know where this is going.