well,I'm still trying to make distinction between mV and MV , even if I'm less often having contact with later
😉
which outputs you're using ?
regarding offset - everything up to 30mV (either +/-) is practically nothing , which means OK
do not bother with normal fluctuations , resulting from change in temp. , because of open/closed lid
😉
which outputs you're using ?
regarding offset - everything up to 30mV (either +/-) is practically nothing , which means OK
do not bother with normal fluctuations , resulting from change in temp. , because of open/closed lid
I'm using the ones in Tea's group buy, this, IRFP240PBF Vishay Semiconductors | Mouser
And a NOS Harris IRFP9240 that tea is supplying for his group buy.
Russellc
Its in system now "reheating" so far, like every Pass DIY piece I have made it is DEAD quite, even on horns...well, half horn half box Econowave.
Russellc
Russellc
Well its playing music....warming up with a little FM. Another 30 mins and I'll start in in earnest, listening to it break in with higher quality sources.
Then upstairs to the vinyl rig, which is where F-6 resides now.
Russellc
Then upstairs to the vinyl rig, which is where F-6 resides now.
Russellc
First notions are that it is a little distant and way laid back with not tons of bass. This is already starting to change, bass much better, less laid back which is good. Needs more time like F-6 did.
Soundstage expanding more, better and better. This parts list I used:
https://docs.google.com/spreadsheet...kL0s0l0HVg6NHbedx5RN8/edit?pref=2&pli=1#gid=0
Russellc
Soundstage expanding more, better and better. This parts list I used:
https://docs.google.com/spreadsheet...kL0s0l0HVg6NHbedx5RN8/edit?pref=2&pli=1#gid=0
Russellc
While M-2 had very good results with horns, things got very interesting upstairs on vinyl system and two way mini monitors.
Ahmad Jamal's Rossiter Road was simply hair raising. May have a new favorite Firstwatt amp!
Russellc
Ahmad Jamal's Rossiter Road was simply hair raising. May have a new favorite Firstwatt amp!
Russellc
My M2 displays some hum with speaker sensitivities >100Db or so.
Room treatments for headphone users
Nelson has made the comment that a slight amount of hum might be present because of the input transformers. At least I think I remember reading this in the past. I have LaScala's and mine is quite but it probably depends on your horns sensitivity. You may try shielding the input transformers or maybe checking your grounding scheme.
I awoke this morning with anticipation of reading your review of this M2 Russellc and was disappointed earlier by not seeing anything but I guess you were too busy listening last night to bother posting anything. I understand. This amp has reached the top of my FW builds as well.
Wouldn't a belly-belt over the input transformers help against hum? At lest it's easyer to build then a magnetic shield.
It seems you guys are having a lot of fun with the M2. Has anyone compared
different output devices?
Cheers,
Dennis
different output devices?
Cheers,
Dennis
Liveliest presentation with FQA, more rocking.
IRF more well tempered.
Over all most convincing SK1530/SJ218 combo, but only with not current demanding speakers.
Do not know why.....
IRF more well tempered.
Over all most convincing SK1530/SJ218 combo, but only with not current demanding speakers.
Do not know why.....
Just a foot note about my 85mv dc offset. I replaced R6 47K resistor with 42.9K resistor and zero'ed my offset without a problem. I had to series a 39K and 3.9K because that is all I had. I did it without removing boards but future builders would be wise to leave R6 and R7 proud of the boards with some extra leads where it will not be a big problem replacing resistors. I sealed it up this morning as well.
On vinyl rig, like zenmod said...F-6 is F-6...this amp is mighty mouse.
Best Firstwatt so far to me.....
Russellc
I have a very few sets of SK1530/SJ218, which FQA devices and are they available?
Russellc
What did you use for input wire? Teabag had a little hum that went away once he replaced input wiring with shielded cable. I used 2 short runs of Silver Sonic BL-2 interconnect cable, which is shielded...no hum.
Russellc