Where did you get the case and heatsinks?rabbitz said:
Do those heat sinks get enough cooling?
Thanks.
made 10's of the Crescendo from 1981 till now and they are superb. Comparing them to a NAD272 just shows that the power output is not as high. But the whole spectrum is crystal clear. The original design had serious flaws in that it would have small oscillations when hitting some frequencies(from music). It showed small spikes in the music on the oscilloscoop. Redoing the Elector PCB by a handmade one and piking good components, included an integrator for the offset, made the whole design absolutely superb and resonance free. Comparing the amp with a powerfull Rotel pre/power amp and NAD pre/power amp shows absolutely clean sound. For me a nobrainer now. Built the ME version also but nothing special really.
Hey just a pup here. I won't turn 53 until June. 😀
I built the P101 as my first amp. I'm listening to it right now. I remember when I first got it up and running, I thought it was weak in the bass, but that's just because I was used to listening to my old Haflers that are a little too bassy IMO.
I built mine three channel thinking I would use it for the front of a 5.1 system. Well I don't have a 5.1 pre yet so I am using it for stereo and driving my JBL B360 sub with the third channel.
Trust me, bass is not a problem. Like others have said, it very easy to build and sounds great.
Blessings, Terry
I built the P101 as my first amp. I'm listening to it right now. I remember when I first got it up and running, I thought it was weak in the bass, but that's just because I was used to listening to my old Haflers that are a little too bassy IMO.
I built mine three channel thinking I would use it for the front of a 5.1 system. Well I don't have a 5.1 pre yet so I am using it for stereo and driving my JBL B360 sub with the third channel.
Trust me, bass is not a problem. Like others have said, it very easy to build and sounds great.
Blessings, Terry
Getting back to the original post. . . .
Rod wrote somewhere that he originally had no intention of using the bootstrap, it was just a temorary measure while he worked other issues. When he went to replace the bootstap, it turned out that mopre "sophisticated" solutions offered little or no improvement so he left it alone. This probably isn't the case universally, I just worked that way on the P101.
The P101 actually has protection:
A- there are intergral catching diodes across the drain and source of inside each output device.
B- the four diodes (2 zenners, 2 switching) bewtenn outpot/NFB and gate - Exicon shows these in an appnote and it's reputed to work well although I've tested it myself. The limitations are: some claim they may be too slow if double die Mosfets are3 used (something Rod does not encourage) and when the activate the rail fuses blow - or so I've been told. Again I have not tested it. Blown fuses might not be accptable for a comercial product, a DIYer sghould be able to deal with it.
Rod wrote somewhere that he originally had no intention of using the bootstrap, it was just a temorary measure while he worked other issues. When he went to replace the bootstap, it turned out that mopre "sophisticated" solutions offered little or no improvement so he left it alone. This probably isn't the case universally, I just worked that way on the P101.
The P101 actually has protection:
A- there are intergral catching diodes across the drain and source of inside each output device.
B- the four diodes (2 zenners, 2 switching) bewtenn outpot/NFB and gate - Exicon shows these in an appnote and it's reputed to work well although I've tested it myself. The limitations are: some claim they may be too slow if double die Mosfets are3 used (something Rod does not encourage) and when the activate the rail fuses blow - or so I've been told. Again I have not tested it. Blown fuses might not be accptable for a comercial product, a DIYer sghould be able to deal with it.
HuntTheShunt said:
I got them from Jaycar in Australia.
http://www1.jaycar.com.au/index.asp
The case had a new anodised front panel installed as the original was quite ordinary powder coated poop coloured thing and the top panel was resprayed. Made by these guys for the pro market.
http://www.chevalgrp.com/pf_19series.html
http://www.chevalgrp.com/pf_19.pdf
The case is now used for an ASKA 55N+ which in the earlier posts was the goal (Hugh's a smooth salesman 😀). Nothing wrong with the P101 BTW as it's gone to other duties and is IMO Rod's best amp.
The heatsinks are a tad smaller than in the instructions (by 20%) but the amps are low power units with single Mosfets running at 49V rails....... runs luke warm only. The case has vent holes directly under and over the heatsinks so there's plenty of air flow.
still4given said:
This is an old guys reunion. 😀
My 2 pennies !
The Crescendo was the worst diy amp ever, i am glad i did not build the ME.
The Crescendo required a big chassis, 2 big toroids, 8 expensive Hitachi Mosfets, 8 expensive +80volt electrolytic capacitors, big heatsinks.
The amp did not do over 50 KHz at -3 dB, and as posted tried to swing itself to the moon.
The Crescendo had a bipolar electrolyte connected to the input of the amplifier on one end, to the feedback at the other, that should be a NoNo today,imo.
Elektor did a number of really nice amplifiers, and i built quite a few, the Crescendo is not a nice one.
Used by many as a subwoofer amplifier, even for a sub the money could be wiser spent.
The Lateral Hitachi Mosfets have not been made in a long time, if you find any they'll probably cost $20-$25 each.
Replacing them by exicon's is an option, but those are very expensive too,imo.
Admitted, i only built 1 Crescendo. 1 too many !!!!!
Today, the size and voltage of the powersupply of that amplifier is enough to build an amplifier doing well over 200 watts, spending it on something as the Crescendo is outdated, a waste of money, and you end up with a bad bad amplifier.
Do as Terry, go for Rod's !
The Crescendo was the worst diy amp ever, i am glad i did not build the ME.
The Crescendo required a big chassis, 2 big toroids, 8 expensive Hitachi Mosfets, 8 expensive +80volt electrolytic capacitors, big heatsinks.
The amp did not do over 50 KHz at -3 dB, and as posted tried to swing itself to the moon.
The Crescendo had a bipolar electrolyte connected to the input of the amplifier on one end, to the feedback at the other, that should be a NoNo today,imo.
Elektor did a number of really nice amplifiers, and i built quite a few, the Crescendo is not a nice one.
Used by many as a subwoofer amplifier, even for a sub the money could be wiser spent.
The Lateral Hitachi Mosfets have not been made in a long time, if you find any they'll probably cost $20-$25 each.
Replacing them by exicon's is an option, but those are very expensive too,imo.
Admitted, i only built 1 Crescendo. 1 too many !!!!!
Today, the size and voltage of the powersupply of that amplifier is enough to build an amplifier doing well over 200 watts, spending it on something as the Crescendo is outdated, a waste of money, and you end up with a bad bad amplifier.
Do as Terry, go for Rod's !
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