[tourmaline]

Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif I wonder if a little bleed circuit couldn't be put together for the Bada that won't harm the signal during use ?.....Use a high quality DPDT (or SPST) 250V 5A toggle (on off on) connected to the filter cap reserves on one pole and current hungry super bright LEDs on the other pole. Have the LED out the signal path in one position for the operate/listening mode and in the that path and on for draining the caps of their current when the unit is shut down and you intend to swap tubes...when the LED has used up all the stored energy it will fade and you can now swap tubes without blowing another mosfet. Maybe a an additional period of say 1 hour after that LED has faded would be better ? Just a guess really. Maybe I'm wrong about this but I have observed my Odyssey SS amp using the LEDs after power down to use up this stored energy, sometimes it takes as long as 45 seconds for the LEDs to fade out ( 120K of filtering). Is there still stored energy in the caps after the LEDs fade ? Maybe so, I need to measure it with a DMM to know for sure. Sorry about the slight OT post everyone. Just thought the idea may help the situation. Peete.

yes there is still energy after shutting off the amp. I measured the power over 24 hours the moment you shut it down, it takes about 24 hours to go to almost zero voltage...the 2 diodes however block any signal comming in above a certain value...so, no problem there. More components in the signal path might mean devaluation of the signal.

 

[pataburd]

The Bada is done, and should be in-hand, God willing, within a week.

Want to post a picture of the innards, but don't know how!

 

[tourmaline]

Quote:

Originally Posted by pataburd /img/forum/go_quote.gif The Bada is done, and should be in-hand, God willing, within a week. Want to post a picture of the innards, but don't know how!

I'll take care of it, no biggy.

 

[tourmaline]

here are pataburd's pictures of the modified bada ph-12:

Looks really nice and a neat job!
I will also post them in the bada thread...

 

[pataburd]

Thanks, Tour. I owe you (another) one! : )

 

[Pricklely Peete]

Quote:

Originally Posted by tourmaline /img/forum/go_quote.gif yes there is still energy after shutting off the amp. I measured the power over 24 hours the moment you shut it down, it takes about 24 hours to go to almost zero voltage...the 2 diodes however block any signal comming in above a certain value...so, no problem there. More components in the signal path might mean devaluation of the signal.

Thanks T...well that settles it...I agree, less is more.

I should measure how long it takes for the Odyssey Stratos's huge cap reserve to drain. Klaus told me when I bought them ( I bought a pair ) they needed 3 days, when powered up, to come to optimum operating status......I still think that's BS but find it amusing to think about from time to time...They are dead simple under the hood...and sound great for a SS amp

They drive Magnepan's and ET LFT VIIIb's, Martin Logan's almost as good as the big Plineus amps for 1/4 the cost.

Peete.

 

[Pricklely Peete]

Are you doing the mods T ? Is there a link to outline the changes done ?

Nice work (in the photos). Looks like a serious upgrade from stock PB.

I bet it knocks your socks off using the Denon cans.

Peete.

 

[pataburd]

Peete,

Here's a list of the mods:

2x V-Cap TFTF 0.47uF/300v to replace the Solen 1.0uF/250v signal caps,

2x V-Cap OIMP 2.7uF/250v to replace the Solen 2.2uF/250v signal caps,

2x Philips LL 150uF/400v electrolytics for the PSU,

3x ERSE 0.33uF/630v capacitors to replace the Wimas soldered to the tube bases,

2x Mills 5W/15k resistors to replace the two resistors inbetween the pair of rear tubes,

4x Mills 12W/100R resistors to replace the two banks of four resistors near the MOSFETS,

3x Mills 5W/8K2 to replace existing PSU resistors,

2x Tanatalum 0.5W/47K resistors to "shunt" the pot,

WBT NextGen pure copper RCA jacks to replace stock,

Neotech UP-OCC, 18AWG, Teflon-jacketed copper hook-up wire,

Both Toshiba 2SK1529 MOSFETs replaced/properly installed, and diodes replaced as-needed.

Fitz graciously consented to do the actual mods (and he shot these pictures which Tour then thoughtfully edited and posted). He is checking a loose/dirty tube socket before officially sending it back.

Can't wait to have the Bada back online, to do head-to-head battle--with both heads being mine--with the Darkvoice! : )

 

[Rednamalas1]

drool!!!

I would also love to see it head-to-head against, say, Millet MAX...

 

[Pricklely Peete]

Thanks PB,

I would have to say you'll hear an entirely different amp from what you remember having looked over the list your provided.....I was wondering what was masquerading under that heat shrink

The Teflon caps I have experience with except mine are the Russian Mil Spec Nos caps. They take a loooooonnnnngggggg time to settle but are the best cap (Teflon is Teflon) on the planet for audio IMHO.

It'll sound great from the get go PB and only improve as the hours begin to pile up. Solen caps are awful IMO...with so many better caps for less money now available, I don't understand why these are used anymore ?

A very intelligent well thought out mod.....I love Head Fi, even though my Wife and the Bank hate it ....

I'm as eager to hear what your impressions are of the Bada Max as you are to get your amp back.....god I'm such a geek ...

Peete.

 

[pataburd]

Peete,
The V-Cap OIMPs are covered with heat shrink (to avoid shorting against their metal bodies).

I give credit where credit is due: to Tourmaline and Black Stuart who very patiently coaxed, encouraged, goaded and advised me through the planning process. And of course to Fitz, who very ably and conscientiously implemented the mods, adding his expert touch, e.g. moving the Erse 0.1uF caps and a pair of the Solen to the other side of the PCB to make more room for the V-Cap OIMPs and the Philips caps; configuring a protoboard to more gainfully implement the pot-shunting Tantalums, etc.

Needless to say, I am in a state of extreme readiness for the mailman! : ) Can't wait to get this Bada hooked back up to the K501!

PAB

 

[Pricklely Peete]

I figured as much...I have to wrap the Russian Teflons in the same stuff when I have some on hand otherwise it's the good old electrical tape to the rescue...

What did the upgrade set you back in the way of cost ? Rough estimate ...

Peete.

 

[pataburd]

Peete,
Cost? Gulp! . . . $500-ish, with about 60% in the V-Caps . . . I stopped precise calculations after $400.

Not a word of this to my (unsuspecting) wife!

 

[Fitz]

You're neglecting to give yourself credit too, Patrick, with how incredibly patient you've been as I ran into some time conflicts and had to work your amp around my busy schedule.

I don't know what the amp sounded like stock (as it wasn't 100% functional before I began), but as it is now it sounds stunning. You're gonna love it.

p.s. The noisy cooling fan just kicked on... that scared the crap out of me! The music went into a quiet passage and at first I thought the amp was about to catch on fire or something.

 

[tomjtx]

hmmmm.........it seems only appropriate that a Fitz 337 mod should be on the horizen.......