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across the bench [season-2] the electron strikes back

getsetgo 300b - 20.jpeg
before the recap and with the 5w capacitor heater in full effect

getsetgo 300b - 21.jpeg
the "max" hot spot isnt up to temp yet, around 265f/129c seems to be the idle point.

please keep in mind this a best case temp scenario i.e. amp is upside down and bottom panel is removed. think for a moment what the temps will stabilize at when the amp is fully enclosed (absolute zero ventilation) and sitting in normal function position. interior chassis temp probably goes beyond 135f/57c after an hour of use, just a guess.
 
getsetgo 300b - 22.jpeg
just about at cruising speed, look at those electrolytics glow. doesnt help that they are flat to the board either.

getsetgo 300b - 23.jpeg
a view top side after the 70w mod installation, note the extra thermal glow far away from the front row 6SL6, rectifier is the max hot spot.
 
getsetgo 300b - 24.jpeg
looks like the 35w chassis mount resistors are sitting around 130f/54c and the board has improved its overall temp.

there are two pairs of diodes creating the remaining hot spot on photo left side. one solution would be longer legs and mounted off of the pcb surface (one pair per side of the board shown).
 
getsetgo 300b - 25.jpeg
other hot spots remain but the 5-to-70 mod will help. a deep dive into thermal corrections is possible for this board.

posting a redundant copy of the pdf files in case the links posted earlier go dark.
 

Attachments

hegel h80 - 1.jpg
hegel h80 integrated amp

hegel h80 - 2.jpg
need to verify functionality and overall condition, basic inspection too

H80

Manufacturer of hi-end audio electronics - amplifiers, preamplifiers, power amplifiers, D/A converters, CD-players and custom installation amplifiers.
www.hegel.com www.hegel.com
 
sae-7125 said:
make sure your annoyance filter is active when visiting the review site, gonna need it.
Click to expand...
The reviewer's idea of critical listening consists of playing ZZ Top over Definitive Technology speakers... At least he's honest and admits he's used to reviewing home theater stuff and was just filling in to help.
 
i wonder if s&s hifi has review article quotas or something, regardless of quality. i remember a small local speaker designer/builder looking into magazine advert placement prices for his products, it was horrific.
 
hegel h80 - 3.jpg
looking inside, fairly basic and easy to construct. mixture of through-hole and surface mount.

hegel h80 - 4.jpg
informative silkscreen. might be able to do a recap in future if a person is truly attached to the brand.
 
hegel h80 - 5.jpg
fairly simple array of drivers and outputs, a few electrolytics near the potential hot zone

hegel h80 - 6.jpg
closer look at the power/filter caps, and some power resistors in close proximity
 
hegel h80 - 7.jpg
trim and bias pots, good to see both in attendance. the board is wearing a layer of dust.

hegel h80 - 8.jpg
some dust removal and a closer look at the thin pcb interconnects
 
hegel h80 - 9.jpg
pic16f1824 programmable chip, if it has a bad day... that could be an issue.

hegel h80 - 10.jpg
toroidal photo opportunity, production year points to what year this h80 may have been produced
 
hegel h80 - 13.jpg
look at the extremely premium grade remote supplied by hegel, starting to see why the review site didnt put much effort into their review.

hegel h80 - 14.jpg
nice amount of ventilation will help. also good view of the hidden power switch.

overall decent/solid build for the chassis. using 3 feet does have its drawbacks though, dont lean on the rear corners.
 
enduro em550 - 1.jpg
spinning in a different direction, comparing a "known good" vs a "known bad" since no schematic exists for these dc motor/servo systems.

variable speed although a log pot is not ideal for something like this. perhaps linear pots were not on sale when these are manufactured.

a somewhat deep dive will be needed to find our what component(s) need repair or most likely replacement.
 
Lab mixers? I have a dead one of those on the bench. It works but it doesn't run at the right speed. Not sure what ails it, but its sort of beyond my willingness and ability to decipher. I checked what i can check but there is something wrong within the head itself. I suspect its a speed sensor problem, no feedback to the controller.
 
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