Rudistor realeased a new flagship amp - Page 2

Last time I checked Kevin wasn't a 2m tall viking so nope, not the same person. 

Quote:

Originally Posted by scootermafia 

I kept up with the progress of that Bellatone amp, and it cost a crippling amount of money to custom make/machine all of its parts.  It's probably one of the few amps out there that costs nearly as much to make as to buy, it'd have to be mass produced to lower its cost.  At least pick the right amp to diss on.

I think the point he was making is this. Well l'll use an example. What if you lace the interior of a honda accord with 1,000,000.00 worth of diamonds. Now that interior is going to be sparkly, and technically that car will have 1,000,000.00 worth or parts in it. But will you pay that much for it. That will be overkill for that type of interior. Will it have the performance of a 1,000,000.00 Bugatti Veyron 16.4? No. That amp may have expensive custom machine parts, but I would rather pay 10,000.00 for and amp that sounded like a 10,000.00 amp.

Now back to our regular scheduled programming

Quote:

Originally Posted by rudi 

btw the heatsinks are fixed to a base of 4mm aluminum, to this base are fixed the loads of current mirrors, all the assembly ( base plus side heatsinks ) work together as heat dissipating systems.
 

Please forgive if this is a stupid question, but does the heat from the amp's current devices have to transmit across the bottom of the casing before reaching the external sinks? If so, how hot does the bottom of of the case get?

Quote:

Originally Posted by scootermafia 

I kept up with the progress of that Bellatone amp, and it cost a crippling amount of money to custom make/machine all of its parts.  It's probably one of the few amps out there that costs nearly as much to make as to buy, it'd have to be mass produced to lower its cost.  At least pick the right amp to diss on.

I don't think Kevin is attacking the actual price cost of the parts in comparison to the final price of the finished product, but is questioning the feasibility of whether someone plans on spending $10,000 on "fancy casework." So you're saying every component of the amp is custom made? If Bellatone or Rudistor wants to charge 10,000 or 5,000 for its amps, I don't have a problem with that nor does anyone else in this thread. Birgir and Kevin are making observations, and I'll trust their observations any day. They also come from a different perspective where maybe casework or R&D might not take up 3/4s of the cost.

*scratches head*

Usually, the load resistor will dissipate about the same power as the power transistor. Considering how small the heatsinks on the power transistors are, it seems quite safe to say that the power resistors used don't need much heatsinking and the bottom of the case by itself should be sufficient. Still, it is puzzling as to why they were not mounted to the heatsinks; the wires attaching them to the pcb would be long enough. The only reason I see is that it's easier to make holes in the bottom than drilling in the heatsinks.

But those unnecessary heatsinks sure look impressive.

lets take a look at this simplified schematic

http://gilmore.chem.northwestern.edu/rp030.pdf

Now its hard to tell what the voltages are on the switchers,

in the past rudi has used +/-12 and +/-15

Lets assume +/-24 as a severe worst case.

The load resistors are clearly labeled as 150 ohms

Assuming that the output voltage before the capacitors

is roughly zero volts, then the power the resistor

is dissipating is 3.84 watts. Even if its 6 volts high

its still 6 watts. So the heatsinks seem mostly for

show.

As far as $10k for an amplifier, Sure i have spent that much,

in fact way more for my krells. When i open up something

that is that much money, i do not expect to find unmodified

DIY boards. I expect the kind of quality you see inside one

of pete's amplifiers for example.  If its audio jewelry on

the outside, it had better have audio jewelry on the inside.

Otherwise you end up with one of mikhail's $15k+ creations.

The Bellatone amp does have some expensive parts like the custom transformers, motorized volume control, separate power supply for auxiliary items, etc.  The casework is a big chunk of the cost, but so is the casework of any high-end product like Krell amps - it's not like the transistors or boards are the most expensive part either.  A B22 is among the best headphone amps and should have a good case and other parts, it isn't like those parts are too good for the B22's boards or something - just like a Chevy 350 belongs in a Corvette but you can buy just the 350 and put it in a Kia (my Beta, which is in a terrible case with an inexpensive vol pot, single transformer single power supply, and numerous other fails).  Having the best supporting parts is like having a purpose-built sports car - while there are fast, cheap cars that can do a quick 0-60, on a track they can't keep up with Ferraris although some might come close.  While having the B22 boards in a case is the most important part (my B22 sounds fine) if I had the money there's no reason not to squeeze every bit of performance out of the B22 design, because it is a great circuit with a lot of potential.  And many people's custom, personal builds have as much spent on casework as other stuff - casework is just expensive, and to make it look the very best, it can add up.  

Perhaps you should declare that you have vested interest in this project?  Aren't you supplying upgraded cables or some other such snakeoil non-sense? 

I've seen the inside of the Bellatone and it is nothing but a gigantic pile of fail.  Long signal paths, BOM parts used everywhere, crappy Plitron transformers, the most stupid way of mounting two boards to a single heatsink that I've ever seen, woefully unreliable motorized DACT, input transformers for the SE inputs and the list goes on and on.  The B22 is a fine amp but for 10K+$ you can get amps built by people who know what they are doing say a Pass XA30.5, Accuphase A60 and have money left over for a proper preamp.   If the aim was to maximize the B22 design then where are the custom designed multilayer PCB's, nude foil resistors, custom built PSU's, bias tracking circuit, transformers built by people who have a clue etc.? 

As for the cost of the chassis, I've done enough custom design (including a fully milled from solid chassis using special aircraft grade aluminum) which has then been professionally anodized and polished to know the costs BJ claims are just nonsense.  I'm also not using China to do my machining but rather Europe and the US so my costs were even higher.  Take the T2DIY chassis, two gigantic boxes using custom extrusions, all milled to perfection and then sent off to be anodized and polished was less than 2k$ each. 

Sorry for the OT, but I'm curious. Have things gone wrong with plitron in the recent years ? They were used in Pass Labs' amplifiers a few years back.

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I'm not even going to comment on the first part of your above post because you are famous for trash-talking and I won't have a discussion with someone like that.

But as far as doing custom B22 boards, that is not allowed by AMB.  If a builder is to sell a Beta22, he must buy the parts from AMB.

But as for the second part where you are saying the costs that I have claimed for the chassis are nonsense, you are wrong plain and simple and spewing lies.  I have received more than enough quotes from many machine shops to do all the parts for this chassis.  When you machine and anodize this many parts on a one-off basis, the costs are extremely high.  Just to do the knobs and power button alone the shops want between $400 - $500 because it's a minimum set-up charge.  I am not producing 100 units at a time.  Having them made in China will save you about 35%, but you will also run into problems as I experienced, having several sets arrived damaged and dinged from carelessness on their end and from poor packaging.  I would never have a production unit chassis made in China.  And if you know where I can this chassis made cheaper locally and be of perfect quality, please, let me know.  I would love nothing more than to keep the cost as low as possible.

Here is what i paid for the T2 chassis

NC machine time per chassis   $630   (10.5 hours @ 60/hour)  Standard price, virtually all machine shops charge this or less

polishing per chassis                $200  (AMS finishing, south side of chicago, amazing work)

anodizing   per chassis             $100  (ATA anodizing in skokie, IL  one of the biggest and best)

All chassis parts including 2 tops, 2 bottoms, 2 fronts, 2 backs, 4 heatsinks, 4 transistor angle brackets, material for 2 stax jacks and 1 knob

                                               $382

(all of the custom extrusions came from M&M metals in Texas which last time i checked was still part of the USA)

total                                        $1312  per chassis

Not even close to what my chassis cost.  Mine are at least twice that.  My front and rear panels are also 5.5" tall by almost 15" W and 5/8" thick.

Also, Kevin, if you have a machine shop you'd care to recommend that does top notch work I'll be happy to send them my CAD files to get a quote and let you know what it costs.

x2