I heard a Lundahl in the M2, I liked the Edcor more.
🙂
And I first used the higher watt version of the Edcor 1:5 and as ZM said more iron than necessary sounded a bit worse.
🙂
And I first used the higher watt version of the Edcor 1:5 and as ZM said more iron than necessary sounded a bit worse.
Last edited:
I totally agree. I just got my M2 up and running using Tea-Bag's boards,Mosfets and Edcors-----big thank you to him 🙂. The sound is great top to bottom with 89db New Large Advents. Lots of bass and sparkling highs. I did not use the jfet buffer, am running it directly from a Schitt Magni 2 (preamp outputs). Lots of drive. Now to spend the rest of the day breaking in and listening to this gem.
I've built an Aleph J and an F6 so I have some reference points.This hobby is really satisfying,build your own and enjoy the fruits of your labour. None of it possible of course without Mr. Pass's generosity and the Diy helpful people ,thank you Nelson and crew.
just go for it
if worry , put steel sheets in those channels in heatsink
as example - they're puttin' two MC xformers in same case ...... and I can't imagine more cautious engineers 🙂
if worry , put steel sheets in those channels in heatsink
as example - they're puttin' two MC xformers in same case ...... and I can't imagine more cautious engineers 🙂
Earthed copper will shield an electric field but not magnetic.
For magnetic shielding, you want iron or something with even better magnetic permeability
nope , just iron will hold (somewhat of) magnetic coupling
however , I'm pretty sure that you can go without
however , I'm pretty sure that you can go without
There is nothing magical about Mu Metal other than an annealing process to improve magnetic permeability through modification of grain structure,
I know two new words today, a electric field and magnetic field and how to shield it.
Thank a lot, ZM and 2Picodumbs.
Thank a lot, ZM and 2Picodumbs.
On P3
As implied elsewhere, I have added a "P3" to my M2 built. That is, a 200 Ohm 20 turn potentiometer over R3 and R4.
To measure the impact of the pot to the harmonics I used the on-board sound of my PC and a little FFT program, suggested in this forum. Measurements were taken at 1W into a 8Ohm resistor.
The result is: the M2 doesn't seem to care about P3, at least not to the level my simple setup allows to be measured. Irrespective of where I turn P3 (and what voltage I get at the input of the autoformer), I measure -92dB for H2 and -83dB for H3. I can use it to cancel the voltage, but that seems to be it.
With a few plugs I can turn my M2 built to become an F5 (same JFETs and MOSFETs). In the F5 configuration I can conveniently dial H2 in and out (below -100dB) while H3 more or less stays at -92dB.
Interestingly, the setting where H2 vanishes seems to be right in the middle of the pot. I guess this speaks to the expert matching by Spencer.
Maybe you find this interesting.
As implied elsewhere, I have added a "P3" to my M2 built. That is, a 200 Ohm 20 turn potentiometer over R3 and R4.
To measure the impact of the pot to the harmonics I used the on-board sound of my PC and a little FFT program, suggested in this forum. Measurements were taken at 1W into a 8Ohm resistor.
The result is: the M2 doesn't seem to care about P3, at least not to the level my simple setup allows to be measured. Irrespective of where I turn P3 (and what voltage I get at the input of the autoformer), I measure -92dB for H2 and -83dB for H3. I can use it to cancel the voltage, but that seems to be it.
With a few plugs I can turn my M2 built to become an F5 (same JFETs and MOSFETs). In the F5 configuration I can conveniently dial H2 in and out (below -100dB) while H3 more or less stays at -92dB.
Interestingly, the setting where H2 vanishes seems to be right in the middle of the pot. I guess this speaks to the expert matching by Spencer.
Maybe you find this interesting.
I can't see a reason for doing that
(ZM: World's Greatest proponent of M2 (sole Papamp which I have no wish to Babelfish ))
Last edited:
In M2 the J-Fets acts as buffers with no gain.
In F5 they deliver gain, I suppose that is the reason you have here big changes.
In F5 they deliver gain, I suppose that is the reason you have here big changes.
I can't see a reason for doing that
(ZM: World's Greatest proponent of M2 (sole Papamp which I have no wish to Babelfish ))
I tend to agree. It's just a fabulous amplifier. Head to head against some very nice kit, it acquitted itself quite well.
Is it possible to use the M2 end stage as a balanced amp?
I want to use two DCB1 buffers in a balanced setup and skip the input JFETS from the M2...
Might be a stupid question...
I want to use two DCB1 buffers in a balanced setup and skip the input JFETS from the M2...
Might be a stupid question...
it is possible , and question is all but stupid
edit : look at F4 for necessary buffer construction precautions
edit : look at F4 for necessary buffer construction precautions
Last edited: