Passive pre-amp?
Most pre-amps will "dampen" the signal anyway? 🙂 .......unless the power amp is a pure "follower"?
Most pre-amps will "dampen" the signal anyway? 🙂 .......unless the power amp is a pure "follower"?
The best resistor is basically Vishay foil and I have an upcoming amplifier build which I am considering using the naked version on the gate and the Powertron on the source and MELF on everything else.
It will be a purebred monoblock version of a stereo amplifier from PASS XA.8 series. I will do things a bit different than the original, but the heart and soul of its father, will be there
At the core of things it is the same but I cannot get my hands on the J313/2013 pair, so I have opted for the IRF610/9610 pair instead. In terms of audiobility, there shouldn't be one. All the other FETs are the same. One could also go for the Toshiba TTC004B/TTA004B pair for the driver stage if one wants to, its more or less equivalent to the 2SC4793/A1737 pair. Point being, such a move, to these alternative FETs in the buffer stage will not be noticeable.
I decided that from now on, my every new thread will either have this as opening picture, or as Title thumbnail (if possible)
2SJ/2SK with 2V Vgs is core of that amplifier. They define lot of things.
I'm having this debate with myself for I might go as high as 4-way loudspeaker., But I don't think using XA.8 on woofers are the most beneficial - that is in an active system. The details and soundstage exist mostly in the midrange and tweeter, so.. lets speculate.
The XA30.8 becomes XA32.8 in monoblock form and I need 4 of them. I then pair this with ZM's XA252 which should have plenty of speed for woofer duty. In this scenario, I need 2 x octets of 313/2013. This makes most sense. I can also do simple by-amping with passive filter or go all active, lots of options.
Building a pair of Purifi class D for woofer duty is ofc also an option, but for now, the scenario outlined above is the most crucial.
The XA30.8 becomes XA32.8 in monoblock form and I need 4 of them. I then pair this with ZM's XA252 which should have plenty of speed for woofer duty. In this scenario, I need 2 x octets of 313/2013. This makes most sense. I can also do simple by-amping with passive filter or go all active, lots of options.
Building a pair of Purifi class D for woofer duty is ofc also an option, but for now, the scenario outlined above is the most crucial.
Here is the data sheet for the 3 W Panasonic ERG MOX resistors .
Not sure if these are magnetic or non magnetic .
https://www.mouser.ca/datasheet/2/315/AOA0000C349-1150021.pdf
From what I understand with resistors , current noise dominates at less than 1 KHz .
So in general , thin film metal foil and wire wound resistors are the quietest in the audio bandwidth .
As a subjective comment , I tried some Mundorf MOX resistors in series with a metal dome tweeter
and they sounded a bit blurred - they weren't too impressive .
When I replaced them with a non magnetic wire wound resistor the sonics were more focused .
I found these 3 W metal films at a good price TE Connectivity Metal Film Resistors RR03JR33TB
https://www.mouser.com/ProductDetail/TE-Connectivity-Holsworthy/RR03JR33TB?qs=HLeXuo0aL2ptw2OFbvbUcQ==
The leads are non magnetic - but the actual resistor itself is .
Another option for power resistors are TKD which make a 2W metal film resistor at a very good price ,
and for larger power ratings , Jantzen wire wound are worth considering .
As for metal film resistors , Pass Labs could be using KOA metal films - but I'm not sure
https://www.koaglobal.com/-/media/Files/KOA_Global/EN/product/commonpdf/mf.pdf
For metal film resistors Dale CMF series are very popular .
https://www.vishay.com/docs/31018/cmfind.pdf
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And some talk about cables. On the pass forum some now talk about resistors. This place will be the talk of the town
Resistors for some, cables for some. What really keeps me awake at night are caps.