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50W monoblock "Engineers Amp"
50W monoblock "Engineers Amp"
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Old 24th January 2017, 09:44 PM   #31
pmillett is offline pmillett  United States
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Originally Posted by overtheairbroadcast View Post
I can better imagine it as, "Why are the lights in the house dimming? Are you making another vacuum cleaner again??"
Oh, it's even better than that. I started down this path when I was pretty young, like 8. Quite often after I rigged something up, I'd get my mom to plug it in for me. There were many sparks and blown fuses.

I do not recall ever doing this... but my dad once told me that I was wiring up something but only had one wire nut to connect the line cord to it, so I put all the wires into one wire nut. Obviously that didn't work too well...

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Old 24th January 2017, 09:51 PM   #32
TonyTecson is offline TonyTecson  Philippines
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learned a new trick, are those 3mm threaded rods Pete?

i am not bothered by how you set that up.....
i too had my shares of bangs and smokes....
planet10 needs your help: Let's help Ruth and Dave...http://www.diyaudio.com/forums/plane...ml#post5010547[B
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Old 25th January 2017, 12:20 AM   #33
Tubelab_com is offline Tubelab_com  United States
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I started down this path when I was pretty young, like 8.
I was about the same age. My parents were more afraid of electricity than I was so I plugged my own stuff in. I did get my father to make me a wooden box with an outlet and a light switch in it. I had to wire it.That way all of my experiments had a "kill switch" that could be engaged by terrified parents, siblings and friends......and more often ME. This practice continues today.

"Why are the lights in the house dimming?......" "Why is the TV acting up again? I told you not to play with that thing when we are watching TV." Those responses were the results of two power consuming, TV jamming projects, the ham radio transmitter and one of several Tesla coil experiments.

None of those experiments resulted in anything more useful than getting myself and some friends banned from entering the high school science fair EVER AGAIN. A middle school project involving the spark coil from a Model T Ford only resulted in that projects withdrawal from competition.
Tubelab, it's 5 year mission. To explore strange new tubes, to seek out new circuits and topologies, to boldly go where no tube has gone before......
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Old 25th January 2017, 01:39 AM   #34
overtheairbroadcast is offline overtheairbroadcast  Canada
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Gee, with the pair of George and Pete, add in all the experiments of mothers plugging in gizmos to tremble coils from Model T's somehow leads into to things like Pete's new Engineer's Amp monoblocks and George's glowing tube behind lexan shield... I am beginning to think that MAYBE I should have stuck that fork into the outlet.

Anyway... Pete, when will we be graced with a few more pictures? The suspense is killing me.
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Old 25th January 2017, 01:44 AM   #35
jackinnj is offline jackinnj  United States
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Just ordered a pair of boards. Will have a duel with the Heath Williamsons! Thanks Pete for the fine work, and George too!
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Old 28th January 2017, 05:44 AM   #36
kolakidd is offline kolakidd  South Africa
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Long time listener, first time caller...

Just checking here for my own sanity, because I am going to have to ship across the ocean, but these are these right Edcor OPT's for the amps: CXPP60-4.2K

The Hammonds + Shipping are resulting in eye bleed.
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Old 28th January 2017, 09:14 AM   #37
trobbins is offline trobbins  Australia
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Good stories of younger days!

Mom ran out of the house and over to my teenager-days construction desk in the shed, yelling frantically if I was ok. The day was very windy, and the aerial 240/415VAC cables running down the street on the other side of the fenceline were swaying heavily, and two cables had touched with an almighty flash and crack.
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Old 28th January 2017, 05:54 PM   #38
Matt BH is offline Matt BH  United Kingdom
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We must all be like minded

When I was 11, so first year of secondary school I made an electric shocker. Just a small backwards mains transformer a 9V battery and a micro switch. I got caught in a science class zapping my friend in the back of the neck. I really thought I was in big trouble. My teacher Mr Turner took the gadget and got everyone in the class to hold hands and gave the whole class a shock. Good times, best teacher I have ever had.

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Old 29th January 2017, 12:38 AM   #39
12E1 is offline 12E1  United Kingdom
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Originally Posted by Matt BH View Post
We must all be like minded
I took a hand-cranked telephone ringing generator to class in the early 1970s - I also had the whole class holding hands and then gave the handle a quick couple of turns. You wouldn't get away with that today, I fear. Too much Elf and Safety.
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Old 29th January 2017, 01:43 AM   #40
smoking-amp is offline smoking-amp  United States
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"are these right Edcor OPT's for the amps: CXPP60-4.2K?"

Those CXPP60 should work fine. Might have slightly different mounting holes from the Hammond 1650N, I don't know. The Edcor OTs are good quality. They are blue. The Hammonds are black. If that makes any difference.


Anyone able to comment on how much buzz/hum from the Hammond power xfmr 290FX versus the 291FX? I know the 300 series (373FX) are dead quiet, but they cost almost 2X.


For 440V B+, one could use an industrial (Ebay) 120V to 480V xfmr with an inductor input DC filter. The inductor may cancel out the cost savings though.


It might be cheaper to just use a 120V:480V industrial xfmr with a cap input (610V B+), and then up the size of the OT to 100 Watt. Rather more dangerous B+ voltage to work with then, only for the experienced builder. Expect some hum from an industrial power xfmr. however, they don't put any extra steel laminations in those.
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