I very much like the bleeding resistor in parallel to the output cap , around 100 ohm . On every zen-like amp . It is almost a must . lol
Well nice question , I am going to work but I'll try a little answer .you mean a 100r between the speaker outputs? what is the role of these?
I, anyway implement the parallel network to my drivers ( fostex ) since this is after all a current source amp .
May want to look at the "current source amps" article , so look also at the eq networks for full range drivers .
Technically I don't know why the additional resistor close to the amp does something particular , but like it and usually notice if it is there or not . ;-)
The other part of the RC eq network is close to the driver .
s
inductor sit
hammond choke on board the operation was successfull , removing one power transformer , and all the series resistor, and heatsink. i put a 25W reosthat for the source variable resistor and bypass it again with 100000uF epcos. i found a nice spot at 18,5V and 1,6amp. less transformer noise, less heat ..
for the sound it seems not as precise as with the thick film resistor load but it sounds even more relaxed and the bass are a little more powerfull. anyway no big difference between the two version.
another 'Merci patron" for michael and his help..
hammond choke on board
the operation was successfull , removing one power transformer , and all the series resistor, and heatsink. i put a 25W reosthat for the source variable resistor and bypass it again with 100000uF epcos. i found a nice spot at 18,5V and 1,6amp. less transformer noise, less heat .. for the sound it seems not as precise as with the thick film resistor load but it sounds even more relaxed and the bass are a little more powerfull. anyway no big difference between the two version.
another 'Merci patron" for michael and his help..
An externally hosted image should be here but it was not working when we last tested it.
Merci beaucoup, juanitox for showing and commenting the inductor solution.
Your words remind me of the Mufollower behaviour, a bit mor gain, a bit more bass but also not so precise as the thick film solution.
I am still making a break in building amps...... I simply want to hear music at the moment....and the differences between the different amps were small so that I could get used to the sound of all of them.....
But my next try will be the self biased solution you preferred and some variants of the CCS and MU again.
See you later French alligator!
Your words remind me of the Mufollower behaviour, a bit mor gain, a bit more bass but also not so precise as the thick film solution.
I am still making a break in building amps...... I simply want to hear music at the moment....and the differences between the different amps were small so that I could get used to the sound of all of them.....
But my next try will be the self biased solution you preferred and some variants of the CCS and MU again.
See you later French alligator!
that's what i'm trying to do between Sit and Dac experience , i have killed dozen of dac into crazy mods.. but the Sit amp ( with source resistor) is invincible even on my hand you are right and michael say it the difference betwwen the two version is so small that i will not going back with the film Resistor , i'm lazy.. the big difference is the heatsink now just warm and the half of transformer power saved. if you want to try the "french taste" you will need the best 100000uf cap ( epcos sikorel or Rifa ph200) bypassed with a 10 /20 uf MKP and swapp the 10uF input cap. if you don't do that it will sound worst than the no-degenaration version
bon week-end ..
Hi 2 all1
Long time gone now - have all the stuff, but wondering bout 1 thing before I get my soldering iron hot and the SK82 in gear!
I maybe bought some resistors that are too big - 47 ohm and 47 kohm - I did buy them at 1Watt. Shall I order some 1/2 or 1/4 watt? They are a VERY good quality(without doubt) - but maybe tooo much watt?
Some clues before I take the last steps - thank you all!!
Ol
Long time gone now - have all the stuff, but wondering bout 1 thing before I get my soldering iron hot and the SK82 in gear!
I maybe bought some resistors that are too big - 47 ohm and 47 kohm - I did buy them at 1Watt. Shall I order some 1/2 or 1/4 watt? They are a VERY good quality(without doubt) - but maybe tooo much watt?
Some clues before I take the last steps - thank you all!!
Ol
A resistor of to high a wattage rating will have no detrimental electrical effects. The wattage rating is important when the actual in circuit power dissapation is close to this rating. Dissapating more than this rating may change the value, permanatly distroy the Risistive film, discolor and corode the body of the risitor and/or your PCB, or even start a fire.
There is of coarse a physical size issue with higher power rated resistors. They are big.
I very often size my power resistors of 5-10 times the needed rating. For instance a source resistor for an output FET may need to dissapate .5W. I would use a 5 or 10W rewsistor in this location. This will help with thermally generated linearity issues and maintaining a more precise value. The increased physical size also radiates the device heat maintaining a reasonable temp on the component and PCB.
There is of coarse a physical size issue with higher power rated resistors. They are big.
I very often size my power resistors of 5-10 times the needed rating. For instance a source resistor for an output FET may need to dissapate .5W. I would use a 5 or 10W rewsistor in this location. This will help with thermally generated linearity issues and maintaining a more precise value. The increased physical size also radiates the device heat maintaining a reasonable temp on the component and PCB.
Hi again FLG and tnx!
Space ain`t the big problem - and there ain`t any pcb either. So with some nice polyprop and those resistors - my build can be finished in a week or two(depends on my household and their wishings these days in my 4 week freedom from offshore-schedule).
And pics will come when the Amp is ready to rock!!
Olav
Space ain`t the big problem - and there ain`t any pcb either. So with some nice polyprop and those resistors - my build can be finished in a week or two(depends on my household and their wishings these days in my 4 week freedom from offshore-schedule).
And pics will come when the Amp is ready to rock!!
Olav
Hi Guys,
Just picked up four 2sk82s from circuitdiy.com. Looking to build the LAMP CCS.
Have a question about a connection. Not sure if it's a bridge in the schematic or a connection point. See attached diagram.
Also, I have a transformer that was used in the original Zen amp. I think it's an Avel-Linberg 28v, 6 amps capable. What is the proper transformer current rating for this project?
What isolation pad is used? TO-3 type?
So, to fire up the amp the first time, the pot is fully open, correct?
BTW- love the CCS!
If anyone is interested, the 2sk82s were $22 each. They also sell them in a set of 8 for $168, and they also sell complimentary N and P channel pairs. They take paypal. The site says they are guaranteed new. They are out of Singapore. I hope I bought the right thing!
Just picked up four 2sk82s from circuitdiy.com. Looking to build the LAMP CCS.
Have a question about a connection. Not sure if it's a bridge in the schematic or a connection point. See attached diagram.
Also, I have a transformer that was used in the original Zen amp. I think it's an Avel-Linberg 28v, 6 amps capable. What is the proper transformer current rating for this project?
What isolation pad is used? TO-3 type?
So, to fire up the amp the first time, the pot is fully open, correct?
BTW- love the CCS!
If anyone is interested, the 2sk82s were $22 each. They also sell them in a set of 8 for $168, and they also sell complimentary N and P channel pairs. They take paypal. The site says they are guaranteed new. They are out of Singapore. I hope I bought the right thing!
Attachments
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Hi Salas
Could you help me, please.
I'm building L'Amp, CCS version, 35V-1,5A current...It's possible to use your Shunt regulated supply instead unregulated supply?
There is some problem with the CCs load, or i have to go direct into SIT?
I have red PCB, could advice about current setting and diodes and trsfos value.
Also, could use same shunt supply for negative bias?
I love your shunt, allmy system it's supply via Shunt!
Grazie mille
Marco
Could you help me, please.
I'm building L'Amp, CCS version, 35V-1,5A current...It's possible to use your Shunt regulated supply instead unregulated supply?
There is some problem with the CCs load, or i have to go direct into SIT?
I have red PCB, could advice about current setting and diodes and trsfos value.
Also, could use same shunt supply for negative bias?
I love your shunt, allmy system it's supply via Shunt!
Grazie mille
Marco
Hello Marco
I will look into it, of course we will continue in the power supplies thread. The only extra info I will need from the guys in this thread is: How much more than 1.5A idle this amp can ask for peak power ref to nominal? Or it does not ever move even with resistive CCS? Thanks.
*With such a supply you will not need active CCS for killing buzz, you can keep it with resistive. Unless you like the sound of active CCS, but most of it is the PSRR and a bit the different THD.
I will look into it, of course we will continue in the power supplies thread. The only extra info I will need from the guys in this thread is: How much more than 1.5A idle this amp can ask for peak power ref to nominal? Or it does not ever move even with resistive CCS? Thanks.
*With such a supply you will not need active CCS for killing buzz, you can keep it with resistive. Unless you like the sound of active CCS, but most of it is the PSRR and a bit the different THD.