watt(what to use...?)
Hi all!
Have found my power resistors on the Bay. I will give more details later w/pictures. And have got a good idea for the enclosurè (it`s a real nice one).
But have to take one step at a time - and today I was thinking what watt/type you use on the R1=47 kohm and what watt/type on the R2 47 ohm? And what Type Capasitor is the C1=10 microF?
The C2 I have bought 2 pc of 10000 microF Nover (marked LA - which should be good for audio)
If anyone - Michael or one more versed in this - could help me out, i would be VERY grateful!
Best
Olav
Hi all!
Have found my power resistors on the Bay. I will give more details later w/pictures. And have got a good idea for the enclosurè (it`s a real nice one).
But have to take one step at a time - and today I was thinking what watt/type you use on the R1=47 kohm and what watt/type on the R2 47 ohm? And what Type Capasitor is the C1=10 microF?
The C2 I have bought 2 pc of 10000 microF Nover (marked LA - which should be good for audio)
If anyone - Michael or one more versed in this - could help me out, i would be VERY grateful!
Best
Olav
resistor ?
well the lamps are beautiful but not simple here in EU , the alogen stick have hi price and not so clear resistence ...plus the philips mbtf only 200hr ,the GE 2000hr but I see only 500w .....
with 39v bias 2A ,speakers 5,5ohm I'm near of Stefano working amp ie 16 to 20ohm needed resistence...
Suggestion?
well the lamps are beautiful but not simple here in EU , the alogen stick have hi price and not so clear resistence ...plus the philips mbtf only 200hr ,the GE 2000hr but I see only 500w .....
with 39v bias 2A ,speakers 5,5ohm I'm near of Stefano working amp ie 16 to 20ohm needed resistence...
Suggestion?
Yes but....
Hi Tea-Bag.
Does a polypropylene meatllized cap have a marking that is + or - dependent. I don`t remember all from my building days( when i built a Hafler Pre-amp and modding an old Sentec Power-amp)
I changed many caps with polyprops in those days - but I sure don`t recall that the caps had any polarity(exept electrolytic caps).
But anyway I will get them Solen when i`m off my offshore schedule in a small week!
Thanks
Olav
Hi Tea-Bag.
Does a polypropylene meatllized cap have a marking that is + or - dependent. I don`t remember all from my building days( when i built a Hafler Pre-amp and modding an old Sentec Power-amp)
I changed many caps with polyprops in those days - but I sure don`t recall that the caps had any polarity(exept electrolytic caps).
But anyway I will get them Solen when i`m off my offshore schedule in a small week!
Thanks
Olav
the sonic difference between Vishay thick film 50Wresistors, less inductive and Dale Vishay metal 50W is very clear, I prefer the thick film.
I combined in the first version 4x 10 Ohm/50W to get again 10 Ohm and added 1x2,2/50W and 2x 1/50W Ohm to get the 14V at the drain with around 44-46V supply voltage.
Both types needs a good cooling area as big as for the SK82 himself, I suggest...
Olav no problem 9.4u..suggestion on SA or Esa series...
hificollective and some Oland shops have in stock
great caps guide Humble Homemade Hifi
bypassing the SA with Vishay MKP1837 is good tricks
hificollective and some Oland shops have in stock
great caps guide Humble Homemade Hifi
bypassing the SA with Vishay MKP1837 is good tricks
Here's my mini-essay on parts.
Firstly, I believe parts make a difference, and some are better than others. In general, though I'm am usually preoccupied with getting a circuit to perform well with average parts. In my amps, I tried KOA carbons, and the usual Dales. For caps I've used Axons, and the plain-old Panasonics. But, at this point, I can't honestly say I've made a serious attempt to evaluate the differences.
Because of their low parts count, these simple amplifiers make great test bed's for trying different parts, and I love to hear about different parts you've tried, so I hope you won't mind if I leave that to you.
May I at least suggest that, before you spend the big bucks on fancy caps and whatnot, invest in the right heatsinking, transformer, etc. After all, which one do you think will make the greatest difference? Once you have a properly performing, neatly wired, non-smoking amp, then you can go for those pricey caps and stuff.
One of these days, though, I plan to really let my hair down and try some of those spiffy caps and resistors. I might even start wearing a tie-dye t-shirt.
Firstly, I believe parts make a difference, and some are better than others. In general, though I'm am usually preoccupied with getting a circuit to perform well with average parts. In my amps, I tried KOA carbons, and the usual Dales. For caps I've used Axons, and the plain-old Panasonics. But, at this point, I can't honestly say I've made a serious attempt to evaluate the differences.
Because of their low parts count, these simple amplifiers make great test bed's for trying different parts, and I love to hear about different parts you've tried, so I hope you won't mind if I leave that to you.
May I at least suggest that, before you spend the big bucks on fancy caps and whatnot, invest in the right heatsinking, transformer, etc. After all, which one do you think will make the greatest difference? Once you have a properly performing, neatly wired, non-smoking amp, then you can go for those pricey caps and stuff.
One of these days, though, I plan to really let my hair down and try some of those spiffy caps and resistors. I might even start wearing a tie-dye t-shirt.
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Hi and thanks....
YES -
from the icy cold North Sea - where I spend my days testing PA-speakers on the stormridden Platforms and wiring optical fibres etc - thanks to everyone, NOW I have many new caps and resistors to ponder when I enter shore from helicopter next week. But I first must grab some 0,5 C/W heat, 400 VA, 4x 37000 powerCaps and stuff it into a nice box(or 2). It is all for the JOY of music.
TNX for all the suggestions!
Best
Olav
YES -
from the icy cold North Sea - where I spend my days testing PA-speakers on the stormridden Platforms and wiring optical fibres etc - thanks to everyone, NOW I have many new caps and resistors to ponder when I enter shore from helicopter next week. But I first must grab some 0,5 C/W heat, 400 VA, 4x 37000 powerCaps and stuff it into a nice box(or 2). It is all for the JOY of music.
TNX for all the suggestions!
Best
Olav
hey guys , the french man is on the road again.. new 800W 10ohm thick film, and 3,3ohm 10W thick film , cheap replacement bridge , 470 uf 63V MKP bypassing the 47000uf master takey output Cap.. the Transfo still do Buzz but i isolate it from the chassis with 2cm neoprene .. so it is cold and less noisy. and at last no noise from the speaker.!? the only thing i have change is changing my death hefred ixys bridge with 3$ ones . sounds is less good but no ringing with the transfo? is it possible?
An externally hosted image should be here but it was not working when we last tested it.
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Has the operating point moved? Give us your Vds, and Id, and the voltage across those resistors.
I hate to obsess, but the temperature inside that case has to be insane. Stuff works differently at 150C than it does at 75C. It matters. Place your temperature probe inside and flip the box over and take a reading after 20 minutes or so.
Are you completely noise free from the listening position?
It's looking good, keep going
I hate to obsess, but the temperature inside that case has to be insane. Stuff works differently at 150C than it does at 75C. It matters. Place your temperature probe inside and flip the box over and take a reading after 20 minutes or so.
Are you completely noise free from the listening position?
It's looking good, keep going
michael you are right , now the buzz is gone , the heat problem i worse than before , i can't put my hand more than 2 seconds on the metal plate . i must re-build the entire amp later.. before i had to try RIfa PEH200 power cap , R-core transfo, and hammond 10h choke in place of the CRC .. do you have a good bridge rectifier model ?with 50V B+ anf 13.3ohm res i'v got now 14V and 2,6amp and could also fry a Egg..