Heathkit W5M Amp need suggestions for....
- Thread starter SixCats!
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Agreed on trying to find an original OPT.
However, if that proves impossible, the output transformer from an Eico HF20 or 22 would definitely work. Or, this Edcor would be the most reasonable modern replacement:
http://www.edcorusa.com/products/440-cxpp50-ms-7_6k.aspx
Regards,
Gordon.
However, if that proves impossible, the output transformer from an Eico HF20 or 22 would definitely work. Or, this Edcor would be the most reasonable modern replacement:
http://www.edcorusa.com/products/440-cxpp50-ms-7_6k.aspx
Regards,
Gordon.
Peerless 16458, that's the good one.
What one do you currently have???
Google it up, you might find interesting stuff like this..
http://www.audiokarma.org/forums/showthread.php?t=47727
What one do you currently have???
Google it up, you might find interesting stuff like this..
http://www.audiokarma.org/forums/showthread.php?t=47727
Hi guys,
Thank you so very much for all your help. I have been contacted by my buddy MARKUS who just so happens to have an "original" OPT for my W5M. Yea baby! GordonW, I am going to keep the information you provided on the Edcor handy just in case the W5M OPT should not be in proper working condition. Andyman, I will have to check out my Heathkit Amp to see which OPT I need. Oooh, Andy, thank you so very much for the W5M link! Thanks again guys.
Regards,
Tom
Thank you so very much for all your help. I have been contacted by my buddy MARKUS who just so happens to have an "original" OPT for my W5M. Yea baby! GordonW, I am going to keep the information you provided on the Edcor handy just in case the W5M OPT should not be in proper working condition. Andyman, I will have to check out my Heathkit Amp to see which OPT I need. Oooh, Andy, thank you so very much for the W5M link! Thanks again guys.
Regards,
Tom
Both will work, but the 16458 is the hard one to find. I had one on the W-5M i found on the curb and wound up having to but a pair online to get a match and wound up with 3.
I wound up swapping around trannys and bases to get a matched set, but never really spent a lot of time with the amps, as I like my little Almarro A205 quite a bit, and they never really wowed me enough to displace the A205.
What kind of power tubes do you have??? Gray coated Genelex KT66s would be nice :yes:
I wound up swapping around trannys and bases to get a matched set, but never really spent a lot of time with the amps, as I like my little Almarro A205 quite a bit, and they never really wowed me enough to displace the A205.
What kind of power tubes do you have??? Gray coated Genelex KT66s would be nice :yes:
jwalker
Well-Known Member
The W5m is basically a classic Williamson with UL taps (not at 43% either). The 16309's that I have have a 10k primary impedance when I measured the turns ratio.
The HF-20 is also technically a Williamson, but it's OPTs are 6.6k primary. The SAM sheet says they are 7.6k or something, but I measured five difference HF20/22/35 opts and they are all 6.6k. I'm pretty sure SAMs is wrong here (not the first time that's happened...)
Williamson needs a pretty high performance (bandwidth mostly) OPT to prevent instability. Maybe Edcors are good enough, but I've never seen a frequency response plot of any of the p-p Edcors.
You're best bet is really to find a Peerless 16309, or a pair of decent 10k williamson OPTs with UL taps on it (not a lot of those around). Maybe custom from Heyboer? They made 10k Peerless clones with added UL taps for PakProtector I believe.
Hi guys,
Ummmm.....I just checked the W5M stored away in my Basement.
There was a note on the unit from the Tech who last checked it out.
The note reads "ONE SIDE OPEN PRIMARY PEERLESS 16458". Darn it! Wouldn't you know I'd have the W5M with the more desirable 16458 OPT that's NOT working! Arrrrrrr! Markus, is that OPT a 16458 ? I also have a PILOT AA-920 Integrated Amp that's in need of an OPT.
Regards,
SixCats!
Ummmm.....I just checked the W5M stored away in my Basement.
There was a note on the unit from the Tech who last checked it out.
The note reads "ONE SIDE OPEN PRIMARY PEERLESS 16458". Darn it! Wouldn't you know I'd have the W5M with the more desirable 16458 OPT that's NOT working! Arrrrrrr! Markus, is that OPT a 16458 ? I also have a PILOT AA-920 Integrated Amp that's in need of an OPT.
Regards,
SixCats!
PakProtector
AK member
hey-Hey!!!,
Send that OPT to Heyboer and have it rebuilt. They'll unwind it and make another one with the same turns/interleave. Or, have them wind up an S265Q for you; that one is also 10k a-a but in 40Watt size instead of 20Watt.
cheers,
Douglas
Send that OPT to Heyboer and have it rebuilt. They'll unwind it and make another one with the same turns/interleave. Or, have them wind up an S265Q for you; that one is also 10k a-a but in 40Watt size instead of 20Watt.
cheers,
Douglas
If there's any problem with bandwidth, you can always do the circuit mod (feedback change) that Bricktop did to his Heathkit W4s (that, IIRC, Jaymanaa has now). If it can make a W4 output transformer behave correctly on square waves with a 1uf cap across the output, it can DEFINITELY make something work with the Edcor transformers...
Regards,
Gordon.
jwalker
Well-Known Member
That's the first time I've heard of the bigger W5m breaking. Folklore has it that Peerless redesigned the 16309 and made it bigger (minus the nickel lams) to get around some reliability problems. The bigger 16458 isn't supposed to break, but I guess nothing is indestructable.
jwalker
Well-Known Member
How much are the latest S265Q repros? I am guessing he can do 50% taps like the W-5m opts?
I think with the better materials today, a rewound 16309 would be as reliable as anything out there. But you'll need to recycle the steel core probably. When I inquired to Heyboer about rewinding two broken ones I have, he mentioned that the cost might be higher if there are any kinked laminations since he can't use the machine to stack them and the potted nature of them is a quite mess to break down.
But rewinding a 16458 would be the great idea. Not only because it's an ideal opt for the W5m that has a conventional core, but Heyboer can record the construction details and clone them at will. (for people like me who want spares!
)
jwalker
Well-Known Member
For sure playing around with the feedback compensation can get it to work. But that might not be so good from a plug-and-play perspective.
I think I saw on another forum somebody managed a high-power KT88 williamson with Edcor opts. They're probably pretty good. It's just that Edcor is pretty tight lipped about some of performance specs.
JonL
Lunatic Member
I've got a W5M with the 16309 transformer. I haven't yet checked it out to see if it's good. (This was a curb find, it's complete w/original tubes and in great physical shape, dunno about its electrical condition.) If a 16309 transformer is still good, is there any way to minimize the risk of failure? Is it simply undersized, and therefore keeping the volume (power) down will protect it? How about speaker impedance? Does that play a role?
