The mono amp...
No... the amp is a mono amp (for a monobloc pair)...so the input is right!
If the amp was Stereo it will need two speakers outputs also...😉
To Patrick:
Input is correct
Connect power supply + to the board +
" " " - " " " -
" the + of the loudpeaker to the output side of the inductor
" " power supply ground to the ground connection near the output inductor
And connect the - of the loudspeaker to the power supply ground...or to the point that connect the power supply ground to the board!!(this depend of the implementation of the circuit!!)
But please...short connections!!
After enjoy the music!!!
Cheers
No... the amp is a mono amp (for a monobloc pair)...so the input is right!
If the amp was Stereo it will need two speakers outputs also...😉
To Patrick:
Input is correct
Connect power supply + to the board +
" " " - " " " -
" the + of the loudpeaker to the output side of the inductor
" " power supply ground to the ground connection near the output inductor
And connect the - of the loudspeaker to the power supply ground...or to the point that connect the power supply ground to the board!!(this depend of the implementation of the circuit!!)
But please...short connections!!
After enjoy the music!!!
Cheers
Re: The mono amp...
I meant that the right hole is input signal, and the left one is input ground. Not something with left and right inputs
🙂
<snip>Tube_Dude said:
I meant that the right hole is input signal, and the left one is input ground. Not something with left and right inputs
🙂
A language issue...
Hi Megajocke!!
Sorry!!!...i haven't understand you right!!
Is because we both aren't talking our native languages...😉
Cheers
Hi Megajocke!!
Sorry!!!...i haven't understand you right!!
Is because we both aren't talking our native languages...😉
Cheers
thanks for the reply's.
i knew that this was a monoblock. the real problem that i was trying to solve was which out of all those wires was +ve power, -ve power, GND and audio output.
i have now solved this problem thanks to pinkmouse.
just one question, what setting should i have the POT (one in the center of the bord) set at (ie what volts).
other than that this amp makes quite a good sub amp.
thanks for all you input.
i knew that this was a monoblock. the real problem that i was trying to solve was which out of all those wires was +ve power, -ve power, GND and audio output.
i have now solved this problem thanks to pinkmouse.
just one question, what setting should i have the POT (one in the center of the bord) set at (ie what volts).
other than that this amp makes quite a good sub amp.
thanks for all you input.
The pot is probably for adjusting the bias current- to do that you will need advice from someone who knows the mosfets. I don't, sorry.
But if it works well, and doesn't run too hot, you can probably leave it for a while.
But if it works well, and doesn't run too hot, you can probably leave it for a while.
The "biased" pot...
Yes the pot is probably for adjusting the bias current or for adjusting the of set voltage...only the schematic can tell ..but i bet that is for bias adjustment...!😉
The typical bias currents for 2SK135/2SJ50 are 100mA per device...
pinkmouse said:
Yes the pot is probably for adjusting the bias current or for adjusting the of set voltage...only the schematic can tell ..but i bet that is for bias adjustment...!😉
The typical bias currents for 2SK135/2SJ50 are 100mA per device...
2SK....
Hi Akersa,
The replacements of the 2SK135 and the 2SJ50 are
the 2SK1058 and the 2SJ162.
They are nearly the same(from specs)but not so in service so look for the good bias...Prefer the old TO-3 ones(for sound and shielding),altough the flat-ones better mount🙂)
The picture that Patrick shows is one of the cresendo from elektor...they had a miniversion (about half the size of the cresendo)
They recommended a current of 100 mA(measured by the 5 resistors of 1 ohm at their sources..)i would settle for 800mA,if you have a big enough cooling!!
They run very hot,but still work,after more then 20 years of service..idle still the same as then..nothing changed..yet...
Happy listening!
Hi Akersa,
The replacements of the 2SK135 and the 2SJ50 are
the 2SK1058 and the 2SJ162.
They are nearly the same(from specs)but not so in service so look for the good bias...Prefer the old TO-3 ones(for sound and shielding),altough the flat-ones better mount🙂)
The picture that Patrick shows is one of the cresendo from elektor...they had a miniversion (about half the size of the cresendo)
They recommended a current of 100 mA(measured by the 5 resistors of 1 ohm at their sources..)i would settle for 800mA,if you have a big enough cooling!!
They run very hot,but still work,after more then 20 years of service..idle still the same as then..nothing changed..yet...
Happy listening!
All TO3 have magnetic leads.
Isn't that to worry about if one goes for the nonmagnetic resistors everywhere ?
Isn't that to worry about if one goes for the nonmagnetic resistors everywhere ?
well,
you'll have to solder the nonmagnetic resistors instead of just letting the leads attract eachother😀 😀 😀
william
you'll have to solder the nonmagnetic resistors instead of just letting the leads attract eachother😀 😀 😀
william
Densen
you wrote:
All TO3 have magnetic leads.
Isn't that to worry about if one goes for the nonmagnetic resistors everywhere ?
__________________
plasma fire
Well i guesss it is:-((
But then there's the Densen-cd,it will demagnitize your whole system,and youre worries will go away once you heard the differance between you're old system against the new cleaned one....do you see the light?
you wrote:
All TO3 have magnetic leads.
Isn't that to worry about if one goes for the nonmagnetic resistors everywhere ?
__________________
plasma fire
Well i guesss it is:-((
But then there's the Densen-cd,it will demagnitize your whole system,and youre worries will go away once you heard the differance between you're old system against the new cleaned one....do you see the light?
New Equivalents!
I belive the company EXICON is now manufacturing/ selling exact replacements for the Hitachi J49.....J56/K134....K176 MOS-FET series. Finally back in print again!
I'm of the cliff without a bicycle here.. I had the bad sense to buy a mint Counterpoint SA-220 amplifier (about $500cdn!! couldn't resist!!), but.. it has the IRF 9241/RF M10N15 FET tranistors in it.
Apparently there is no replacement............
Does anyone know about these puppies?
I belive the company EXICON is now manufacturing/ selling exact replacements for the Hitachi J49.....J56/K134....K176 MOS-FET series. Finally back in print again!
I'm of the cliff without a bicycle here.. I had the bad sense to buy a mint Counterpoint SA-220 amplifier (about $500cdn!! couldn't resist!!), but.. it has the IRF 9241/RF M10N15 FET tranistors in it.
Apparently there is no replacement............
Does anyone know about these puppies?
Old amplifier built around 1981-82
Hi Per,
I know it's a long time ago, but try to ask you anyway.
Working with valves one old amplifier with SJ50/SK135 turns up in the memory all the time. I have bought 8 pairs of mentioned Hitachi's mosfets. I attach a copy of the old circuit - it sounds very good and I just want to hear your opinion of the schematic.
Thanks
Kim, Denmark
Lot's of guys here (including myself) have built amps with K135/J50 so if you want some input ask.
Hi Per,
I know it's a long time ago, but try to ask you anyway.
Working with valves one old amplifier with SJ50/SK135 turns up in the memory all the time. I have bought 8 pairs of mentioned Hitachi's mosfets. I attach a copy of the old circuit - it sounds very good and I just want to hear your opinion of the schematic.
Thanks
Kim, Denmark
Attachments
It looks to be a variation of the old Hitachi application notes... there were many offerings at the time and kits too.
I'm a huge fan of Laterals 🙂
If you like the musical sound many good valve amps produce then have a look at this one of mine as well,
http://www.diyaudio.com/forums/solid-state/119151-my-mosfet-amplifier-designed-music.html
Here's the Hitachi variation as an old Maplin kit... this had a real following at the time.
I'm a huge fan of Laterals 🙂
If you like the musical sound many good valve amps produce then have a look at this one of mine as well,
http://www.diyaudio.com/forums/solid-state/119151-my-mosfet-amplifier-designed-music.html
Here's the Hitachi variation as an old Maplin kit... this had a real following at the time.
Attachments
I have looked at the schematic of your mosfet amp. Looks good and symmetrical to me - with rails of +-45Vdc and servo feedback - I am not audio engineer.
My friend is and he claims that: 1. power fets should be driven with stronger drivers than expected. 2 He do not like power fets because of the different act of N and P fets.
I say : I like like the mid-and highrange sound better from mosfets than bipolar, but would like to have a little better attack in the low frequence area.
I have tried with +-45Vdc on the attached schematic of mine but I reached better control of the 12" woofer with +-70Vdc on the double pair Hitachi 2SJ50/2SK135.
I have found ( for me) the best sound in midrange and highrange in L58A with the sj44/sk163 but lack of control because of only one pair 34/149 powerfets.
The intention is to make the Luxman drivercurcuit with a doublepair powerfets. It is hard to find the sj44/sk163 today.
I think that the BF760/BF757 in my circuit drives the powerfets very good - one might find better drivers today than the old Motorola types.
rgds.
2sk227/2sj83
7 years too late!!
The mentioned powerfets from Hitachi was used in 1981-1983 by a danish company in a 100w mosfet amplifier. Compared to 2SJ50/2SK135 they messured better in the same aplication - Hitachi told them to be identical to 50/135 but we could not get any datasheets from the factory at that time!
I have 3 pdf. files with specs for 2SK227/2SJ83.
rgds.
7 years too late!!
The mentioned powerfets from Hitachi was used in 1981-1983 by a danish company in a 100w mosfet amplifier. Compared to 2SJ50/2SK135 they messured better in the same aplication - Hitachi told them to be identical to 50/135 but we could not get any datasheets from the factory at that time!
I have 3 pdf. files with specs for 2SK227/2SJ83.
rgds.
The soundcraftsmen amps use the K135/J50 pairs and they are still a fav. not the best i have heard but there is something about them that is very listenable.
Have never heard "The Soundcraftsmen" mosfet amplifier. I have ones tried with the Borberly drivercircuit without luck and buz900/905. I do have in mind that the buz´s did not sound like the original Hitachi's - might be wrong on this one.( have bought 16 pcs of the original)
Still find the erlier attached circuit as one of the better mosfet amplifers. Is it possible to attach the Soundcraftmen schematic?
Rgds.
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