I saw one at a picture from BAF2016. So i googled this:
Pass Laboratories XA25
Read the description and look at the artwork picture. A new amp SE with hockeypucks. 700W 40 A 😀
Nice!
Pass Laboratories XA25
Read the description and look at the artwork picture. A new amp SE with hockeypucks. 700W 40 A 😀
Nice!
yup
I was puzzled by that picture,too
just starting Babelfishing , though having just thyristor pucks at hand
who know , maybe it'll work .....
I was puzzled by that picture,too
just starting Babelfishing , though having just thyristor pucks at hand
who know , maybe it'll work .....
Based on specs it's almost certainly push pull, but the description "single ended circuitry" seems to contradict that.
More Papa magic by the sound of it.
More Papa magic by the sound of it.
Last edited:
with IXYS IXFN ?
Two transistors beacause CCS maybe ?
Always interesting amp non surprise....oh yes 🙄
Attachments
Yeah certainly possible, even Mu Follower can exceed well past the quiescent bias point if setup correctly.
Last edited:
Single ended may even mean that the circuit is just not a balanced circuit like the rest of the XA series.
I'm not willing to bet the house on it either way.
I did a quick mock-up in SPICE based on the description linked in the first post. While just a basic mu-follower, it simulates very well and matches the stated specs fairly well.
clever cheapskate can always joggle with approach to and difference between balanced , symmetrical and differential .......
The only problem is, this seems to suggest a different front end,
"The simple front end circuit uses uses two pairs of NOS complementary Fets in common-source mode"
If you look at the F1 it's described as a Ballenced Single ended so I assume the same term could be applied to the X series of amps. FIRST WATT F1
The latest XA .8 series amps have complementary push pull output stages, although they do have a small amount of single ended bias.
I wonder whether a Taylor Current Source (source follower output) might be used.
Would that be considered single ended? Or is that cheating.
Would that be considered single ended? Or is that cheating.
The artwork linked above doesn't show the two large power resistors mounted to the center heatsink on each side.
Yep, I accounted for that. Used complementary JFETs in front end with IXYS mu-follower on output. Got results which were pretty close to the published specs. Power output matched into 2, 4, 8-ohms, distortion at 25W into 8-ohm was similar, but max power distortion into 2, 4-ohms was higher in my simulation.