I have a good reliable source
His name is Spencer Cheung
skcheung68 - AT - hotmail - DOT - com
Just ask him what you require for pairs or quads and Idss
Example of what I bought from him:
8 pairs matched in 2 quad (4x K170 and 4x J74). Price is 8x $4.5 = $36
Shipping add $4 and paypal add 5%. Thus total is US$41.6
He's member of DIYaudio forums and sold over 30K units in the last three yrs. Genuine parts only!
Ciao!
Do
His name is Spencer Cheung
skcheung68 - AT - hotmail - DOT - com
Just ask him what you require for pairs or quads and Idss
Example of what I bought from him:
8 pairs matched in 2 quad (4x K170 and 4x J74). Price is 8x $4.5 = $36
Shipping add $4 and paypal add 5%. Thus total is US$41.6
He's member of DIYaudio forums and sold over 30K units in the last three yrs. Genuine parts only!
Ciao!
Do
Yeah, what John said!
I really have no idea how important or effective thermal coupling between singles might (or could) be. Any comments on that question?
Just match them to about 1ma Idss, and put them close together, even superglue them, if you want, flat face to flat face. Don't worry about pin out with Toshiba, S and D are interchangable .
My attention has been diverted by a simple job that turned complex, the failure of a charger on my portable, and other tasks unrelated to the build. The remaining pcbs arrived along with Lucian's i2s interface but I have been unable to do the polystyrene matching or find suitable r-cores. John's letting me know the matching tolerances has simplified my complementary search considerably.
It will likely be next week before things stabilize :-( It has occurred to me that a pair of 24v deep discharge batteries might have been quicker, easier, and less expensive in both the short and long term. Snow expected Thursday 🙂
It will likely be next week before things stabilize :-( It has occurred to me that a pair of 24v deep discharge batteries might have been quicker, easier, and less expensive in both the short and long term. Snow expected Thursday 🙂
What are all those PCBs you're talking about? I'm curious! 😀
The I2S interface is for a DAC a presume? If yes, which one are you using?
Have fun with all the stuff you're working on! BTW, we were treated pretty nicely with snow today. Everything is white... Winter... meh! Time to let my Aleph 5 heat up my room...
Ciao!
Do
The I2S interface is for a DAC a presume? If yes, which one are you using?
Have fun with all the stuff you're working on! BTW, we were treated pretty nicely with snow today. Everything is white... Winter... meh! Time to let my Aleph 5 heat up my room...
Ciao!
Do
Is it within the realm of reason to build a 4 channel JC-80 controlled by a 4 gang stepped attenuator? I hope to build a 4 channel pre to use after my DCX2496 in an active 2-way system.
Given my need to Google the DCX2496 I am likely not qualified to render an opinion.
@pinnocchio, JC-80, Kubota, and OPC's 8xLM49600 amps. The i2s interface will feed some of the fourteen WM8740's around here. Initially it will get wired into a dual mono Opus pair so I can direct ripped bitz from the NAS. Its reclocked (3ps jitter) parallel stream should bring some order to the mix of bit rates and depths that reside out there.
Immienentdomain
4 channels of balanced volume control will have to be some sort of relay based attenuator like Twisted Pear Joshua tree as analog pots don't have enough sections. I don't think you want to use CS 3310 type controls ( they have 8 channel version) as the whole reason to build discrete high current preamp is to avoid the opamp in the CS3310 type chips in the first place. You will have to also look at upgrading / eliminating the internal output stage of DCX2496 or it's not worth doing.
Wolfsin - clever boy ! Digital isn't my thing - I know less than least significant bit , but appreciate the results of other's expertize. I can't distill Scotch, Rum, Tequlia, wine, beer, etc either so i rely on the best efforts of others on sale at local purveyor of fine spirits. Which reminds me i'm due for a visit.
4 channels of balanced volume control will have to be some sort of relay based attenuator like Twisted Pear Joshua tree as analog pots don't have enough sections. I don't think you want to use CS 3310 type controls ( they have 8 channel version) as the whole reason to build discrete high current preamp is to avoid the opamp in the CS3310 type chips in the first place. You will have to also look at upgrading / eliminating the internal output stage of DCX2496 or it's not worth doing.
Wolfsin - clever boy ! Digital isn't my thing - I know less than least significant bit , but appreciate the results of other's expertize. I can't distill Scotch, Rum, Tequlia, wine, beer, etc either so i rely on the best efforts of others on sale at local purveyor of fine spirits. Which reminds me i'm due for a visit.
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LM49600
You have 8 of those LM49600! You lucky man, to not say another word! 😀
Enjoy! It shall be great!
You will just have to solve the heat dissipation issue they're talking about on the forum... Or better, let them figure it out! 😉
Do
You have 8 of those LM49600! You lucky man, to not say another word! 😀
Enjoy! It shall be great!
You will just have to solve the heat dissipation issue they're talking about on the forum... Or better, let them figure it out! 😉
Do
actually he probably has 16, its 8 per channel (unless hes stuffing only part of the board?), hes driving headphones though, so wont have the issues associated with driving a 4 ohm load with them at full power.
heat issues are solved with any of the solutions presented, we are just pontificating about the completeness of the solution for ALL climates and ALL use cases; with a sprinkle of vanity thrown in
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I thought he meant he had 8 of those LM49600 amp boards...
Good for the heat issue resolved! Nice work!
Do
haha now that would be something!!
hochopeper and i havent sorted out our solution just yet, as we havent finished design of the custom chassis. but the heat issue is under control for the majority and we could sit right now with any of them, but we gonna have some fun with cnc 🙂
hochopeper and i havent sorted out our solution just yet, as we havent finished design of the custom chassis. but the heat issue is under control for the majority and we could sit right now with any of them, but we gonna have some fun with cnc 🙂
Wolfsin is basically a single threaded kinda' guy whose delivery latencies force him into pseudo-multithreading. Then, when too many things show up at once he goez into a busy-wait loop 😱 Such iz hiz current status.
jazzm's recent crash took a serious toll but opc and qusp got him thru it better than I could have imagined 🙂
jazzm's recent crash took a serious toll but opc and qusp got him thru it better than I could have imagined 🙂
Heat Sinks that fit!
Something simple -- heat sinks from Sunelectronic available on eBay, qty 8 shipped for less than US$8 total and the pins fit into the pcb holes.
TO-220 Small Power Aluminum Heat Sink 8 pcs
brand new Sku: HSK-TO220-353512-BK-8
Small size aluminum Heat Sink, Black color,M3 Screw Hole
35 x 35 x 12.5mm ( 1.38 x 1.38 x 0.49 inch) for TO-220 package.
Not as tall as pinocchio's but for those with shorter noses . . .
Something simple -- heat sinks from Sunelectronic available on eBay, qty 8 shipped for less than US$8 total and the pins fit into the pcb holes.
TO-220 Small Power Aluminum Heat Sink 8 pcs
brand new Sku: HSK-TO220-353512-BK-8
Small size aluminum Heat Sink, Black color,M3 Screw Hole
35 x 35 x 12.5mm ( 1.38 x 1.38 x 0.49 inch) for TO-220 package.
Not as tall as pinocchio's but for those with shorter noses . . .
If the pins are a match it is a reason alone just to buy them! I had to work quite hard to make them fit! The holes are not standard size for what we have here...
Ciao!
Do
Ciao!
Do
Wolfsin recalled the expressions of joy coming from Montreal regarding those pins. When they fit we observed a momemt of silence here 
I am a bit stuck until I get appropriate r-cores. If I populate the boards too soon it will be harder to measure the noise of the power train alone and I really am curious. We have lots of fresh snow to blow from the driveway so I am not exactly bored but . . .
I am a bit stuck until I get appropriate r-cores. If I populate the boards too soon it will be harder to measure the noise of the power train alone and I really am curious. We have lots of fresh snow to blow from the driveway so I am not exactly bored but . . .
I guess you did! If only I could have found them before! No worries, I had a few cold ones while fixing all this... It made things much smooother 
But at least I have some good working transfos 😉
Ciao!
Do
But at least I have some good working transfos 😉
Ciao!
Do
I got 4 boards and 16 of the heatsinks since John Curl personally approved of the PCB layout. 😀😀😀
Guess I'll start rooting up the other odds and ends while things are in transit from East Asia.
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