The template I posted was designed for those heat sinks. I have a milling machine, but I actually prefer to tap those heat sinks with a tap in a cordless drill. Very good quality extrusions. As long as you keep everything cool and clean, tapping is very easy.
Huh! Cool )) Never tried it with one pair 🙄
With all tree pairs in place - being capable of providing more current at the output, when required - you will like it even more 😎
Thanks xrk,this is a highly recommended amplifier!
Nice!!! Sweet looking amp.
Congrats on first sound!
You must listen to this.🙂😉
Actually I plan to - it's on my "to build" list. I already have VHEX+ and am very impressed with its performance. This one is supposed to be levels above that one.
Perhaps on a scale with Putzeys' ExtremeA?
Perhaps on a scale with Putzeys' ExtremeA?
Yes i know Valery,this was a very first try under biased(small heatsink) low voltage +/-32v,no protection,one pair out only ,but couldn't wait for a first listening test😉
Last edited:
Hi Valery,
I may have asked this before but I can't find it. Will this NS OPS work with MJL21193/94? I have a pile of those.
Thanks, Terry
I may have asked this before but I can't find it. Will this NS OPS work with MJL21193/94? I have a pile of those.
Thanks, Terry
Hi Terry,
I will look at it tomorrow. MJL21193/94 have got much lower fT. Need to check a few things, including stability matters.
Cheers,
Valery
I have another question. Most of my stock of SMD resistors are 0805 (1/8W). Are there many of the resistors in the little IPS boards that need to be 1/4W or can I use the 1/8W parts?
Thanks, Terry
Thanks, Terry
If you can check that each resistor's continuous dissipation is below 50% of that 1/8th watt rating, then your 805s are OK, i.e. <60mW. Feedback resistors should probably be kept below 10% of max rating at peaks of output.
Some 805s are higher wattage. I have a few I got from Digikey that are ¼W
Some 805s are higher wattage. I have a few I got from Digikey that are ¼W
I don't have any way to do that at this point. I am populating the boards. I assume that Valery has run sims on all of these little IPS units so it should be relatively simple to check the dissipation. While I 'm in the questioning mode, It looks like the IPS runs on +-15V. Why are the caps rated for 100V?
Thanks, Terry
Thanks, Terry
Power supply for input stage is +/-15v,power supply for drivers and vas is the rail supply after passing a capacitance multiplier.
Attachments
Last edited:
Hi Terry,i will wait for your listening impressions😉
Be careful with inp. transistors orientation!
Last edited:
Hi Terry,
I ran a number of simulations - NS-OPS is showing reliable performance with MJL21193/94. Slightly higher level of distortion at 10-20KHz (overall open loop bandwidth is slightly narrower), however - insignificant.
Worth testing.
Cheers,
Valery
Good question. All of 1/4W can be replaced by 1/8 ones, except R9, R13 (8.2K) - those ones have to be 0.25W. BTW, 8.2K is a good value for the rails around +/-52V DC. For the higher rails, the value have to be re-calculated for maintaining the same current through these resistors.
All 1W resistors have to be 1W ones.
Cheers,
Valery
Attachments
On small IPS boards - all of them are ok to be 1/8W, except the 1W ones, of course.
dissipation is current times voltage.
You get those from the schematic.
These will be quiescent dissipations and signal only adds a bit to these, except for output emitter resistors and Zobel and such that have very high signal currents..