Wild Burro Betsy OB Build

[danvprod]

Originally Posted by cervelorider

I'll message you the differences (many) as I don't want to hijack danvprod's speaker thread. Btw, I will solder a 3112 board at no cost for anyone who wants one, but doesn't have the tools or desire to sling solder.

Hijack away -- I think the amp is as important to the build as the drivers or enclosures/baffles.

[cervelorider]

In short, the TPA3122 and 3110, in my opinion, gets one very close to the triode sound for $30.
(I've owned a half dozen or so triode tube amps)
Read all the hub bub on the forums about the sonic t amp. The 3110 and 3122 are better yet, especially in the bass depth and authority department. Better sonically than gainclones I have owned.

Jerry's kit allows for a plug and play solution with volume pot and RCA connectors. It's a through hole pcb, so modding is much easier. The Sure 3110 assembled board requires adding a volume pot, rca's and thus a chassis would be advised.
The Jerry TPA3122 is also twice the power if one uses two 12 volts in series.
Sonically speaking, both are wonderful sounding and preferences between the two would be system and taste dependent.

[xrk971]

Thanks for the info Dan. Great to hear that you have first hand experience with them and they sound like good triodes. I may have to try this...

[cervelorider]

Again, if anyone wants to try one of these rascals out, but doesn't solder, I'm happy to assemble either at no cost. Just pay actual shipping from me to you plus parts cost.

[danvprod]

Originally Posted by xrk971

Thanks for the info Dan. Great to hear that you have first hand experience with them and they sound like good triodes. I may have to try this...

Yea -- going to do a comparison with my bro's Decware Mini Torii. My perception is that this amp is right there, which is amazing for a $35 amp IMO.

...Now onto the speakers.

I'm thinking they are a bit too bright right now. There seems to be a 10 dB bump or so at 3 kHz. I hope to have some time this afternoon to do some more detailed measurements.

For kicks, I did try a series 20 Ohm 10-Watt resistor, but quickly removed it because I was not fond of what it did to the phase response. That is, it seems to affect the imaging and slow down the music a bit, if that makes sense.

I know the BetsyKs are going to break in a bit more -- and I am going to get them replaced in early March with regular Betsys because of the left driver issue.

So anyone have any ideas on how to tame that 3kHz bump? Maybe some driver bracing? Weighing down the bottoms of the baffles for some additional bass reinforcement? Some damping on the back?

Maybe a driver brace like this build?
http://diyparadise.com/forum/index.php?topic=1090.0

I am open to ideas.



Dan

[cervelorider]

Originally Posted by danvprod

Yea -- going to do a comparison with my bro's Decware Mini Torii. My perception is that this amp is right there, which is amazing for a $35 amp IMO.

...Now onto the speakers.

I'm thinking they are a bit too bright right now. There seems to be a 10 dB bump or so at 3 kHz. I hope to have some time this afternoon to do some more detailed measurements.

For kicks, I did try a series 20 Ohm 10-Watt resistor, but quickly removed it because I was not fond of what it did to the phase response. That is, it seems to affect the imaging and slow down the music a bit, if that makes sense.

I know the BetsyKs are going to break in a bit more -- and I am going to get them replaced in early March with regular Betsys because of the left driver issue.

So anyone have any ideas on how to tame that 3kHz bump? Maybe some driver bracing? Weighing down the bottoms of the baffles for some additional bass reinforcement? Some damping on the back?

Maybe a driver brace like this build?
Open Baffle Speakers...No Bass??? Try this...

I am open to ideas.



Dan

Your observations parallel mine exactly of the Betsy K vs. the Betsy in an open baffle. The Betsy K is not nearly as successful in an open baffle as the Betsy...IMO. It does have a peak, very similar to a Fostex 206e, when used this way. (the resistance tames it, but not enough) My advice would be not to go crazy trying to tame it, but instead, wait for the Betsy's to arrive and there will be peace and goodness in your audio world.

[zimmer64]

Have a similar observation with my Besty's. Got them this week and built the winged baffles today. One of the drivers makes rattleing noises on some test tone frequencies. On 63hz, the noise comes from within the driver (maybe voice coil or something else). On some higher frequencies, the noises seem to be generated by the basket / magnet as it can be suppressed when I hold onto the magnet. The other driver does not make the noise. So, bracing might work. At least at some frequencies.

The sound overall ain't bad though. I used my Bottlehead Quickie, LM3875 Gainclone and 47 Treasure CD player. My little class D amp I found a bit to weak. Wide and deep soundstage. Quite natural sound. Bass response is quite sensitive to placement. They lack a bit of bass, there isn't much below 60hz. I tried Classical music (Karajan, Beethovens 1st and 2nd Symphonie; Deutsche Gramophon recording from the 60's on CD/SACD), which was fabulous. Jazz: So far I have tried Manu Katche, Miles, E.S.T, Lady Day, Ella, all wonderful. Voices are really great. Very musical presentation. Again, a bit lack of punch in the low octave. Overall, price performance is good. I think my Jordan's are better balanced though, but the EAD drivers are also tripple the price....

Best

Michael

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