"120Watts of Hi-Fi Power" by David Hafler

I just acquired an issue of "Radio and TV News" dated February 1959,and inside is an article written by David Hafler himself describing a Mark III modification,allowing a power output of 120 watts,and a second set of output tubes and using only one 6AN8 driver tube!! He goes into detail of the use of other various driver curcuits,and concludes that with just one modification to the original "Mark III" driver curcuit, which would yield the best results,being a single 600pf/ 1000v capacitor to the original curcuit design,and maintaining a close tolerance in resistor values for the triode phase splitter would give the best results. If anyone is intrested, I can scan the entire article and post it.

The magazine was a great find, an in excellent shape.

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Scan and post!!

Please scan the article and post it!!

Thanks in advance.

.

Of COURSE, we'd like you to scan and post!!!

two extra KT88 tubes plus an extra GZ34 rectifier tube

tubes4hifi wrote:two extra KT88 tubes plus an extra GZ34 rectifier tube

My apologies,thanks for the correction.

Hi Denny:
Great posting. Please post the article ASAP. dying of curiosity.
Merry Christmas
Baddog

Here's the article. I have provided the link to the PDF file. Thanks for your intrest.

120W of Hi-Fi Power_by_David_Hafler.pdf

Looks like new iron as well

I have a PDF of the article that is not a scan. Very good quality. Where can I post it for downloading on the forum?

Did the pdf of the Hafler article ever get posted?

baddog1946 wrote:I have a PDF of the article that is not a scan. Very good quality. Where can I post it for downloading on the forum?

I would think that there would be some sites similar to photo bucket or others that would allow you to upload various different file formats,if you didn't have a web server available.

the high quality PDF provided by BadDog is now hosted and posted on my website here:
120w UL amp by David Hafler
first page is blank, then 3 full pages

I haven't had a chance to actually implement this design because
Of other projects, but I would be interested to hear if someone else has
Tried, I do plan on this in the near future.

denny9167 wrote:I haven't had a chance to actually implement this design because Of other projects, but I would be interested to hear if someone else has Tried, I do plan on this in the near future.

Denny, I say go for it. On a slightly different note, back in the 90's I found an article from a 1957 issue of "Audio Engineering" magazine with a design for a rear loaded, folded horn speaker cabinet. I decided to build a pair (testing the limits of my woodworking skills!). I am still using these today in my "home theatre" system. My hi-fi system, of course, is all Dynaco...all the time!

Best Regards,
Charlie

wbain and probably many others . . .
I rarely "log-off" of this forum but I did yesterday and then noticed this morning that the LINK doesn't show up at all
unless you are logged-into the forum!!

tubes4hifi wrote:wbain and probably many others . . .
I rarely "log-off" of this forum but I did yesterday and then noticed this morning that the LINK doesn't show up at all
unless you are logged-into the forum!!

I finally came to that realization myself.