HIWATT 400 - any queries?
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HIWATT 400 - any queries?
Guys,
I do some hobby work tube amp fixes. More now since I turned 60 and went 3 days per week in the electronic design eng. day job.
Last night a guy dropped a Hiwatt 400 to me for a retube and bias set.
If you have queries relating to these amps I have one open on my bench at the moment so now is your big chance.
Feel free to post any questions here and I'll help if I can. Might be slow in responding but should get around to answers sooner or later.
Cheers,
Ian
I do some hobby work tube amp fixes. More now since I turned 60 and went 3 days per week in the electronic design eng. day job.
Last night a guy dropped a Hiwatt 400 to me for a retube and bias set.
If you have queries relating to these amps I have one open on my bench at the moment so now is your big chance.
Feel free to post any questions here and I'll help if I can. Might be slow in responding but should get around to answers sooner or later.
Cheers,
Ian
Re: HIWATT 400 - any queries?
Don't hurt yourself, mate!
I build and repair tube amps. http://amps.monkeymatic.com
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- Posts: 530
- Joined: Mon Nov 14, 2011 2:29 am
- Location: Adelaide, South Oz
Re: HIWATT 400 - any queries?
Xtian - I'll be properly careful.
I did my electronics training while working in a major hospital (way back when) - one of the bits of gear I used to fix was a 700W RF Surgical Diathermy with 2000 Volts at 1 Amp on the anodes of the push pull (Class C) transmitter pentode output tubes.
Should be able to safely negotiate the "pissant" 600V or so on the 6 x KT88 outputs for this amp - not to make light of the risk mind you. 600V can kill you just as dead as 2000V.
Plan is to match the 3 parallel KT88 on each side of the push pull (on my AVO MK3), set the bias voltages (1 per side ONLY) to max negative volts and then power up.
When I'm happy with no smoke, do the final bias adjustments.
I do not like the look of the bias adjustment pots. Will fit new ones before proceeding.
Cheers,
Ian
I did my electronics training while working in a major hospital (way back when) - one of the bits of gear I used to fix was a 700W RF Surgical Diathermy with 2000 Volts at 1 Amp on the anodes of the push pull (Class C) transmitter pentode output tubes.
Should be able to safely negotiate the "pissant" 600V or so on the 6 x KT88 outputs for this amp - not to make light of the risk mind you. 600V can kill you just as dead as 2000V.
Plan is to match the 3 parallel KT88 on each side of the push pull (on my AVO MK3), set the bias voltages (1 per side ONLY) to max negative volts and then power up.
When I'm happy with no smoke, do the final bias adjustments.
I do not like the look of the bias adjustment pots. Will fit new ones before proceeding.
Cheers,
Ian
Re: HIWATT 400 - any queries?
Post some pictures. Always fun to see something I'm not likely to see in person.
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Re: HIWATT 400 - any queries?
Dropped is operative word as they weigh a whole bunch! Do you folks think about getting a extra bench charge for these Amps and SVTs like I do at times?
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: HIWATT 400 - any queries?
Yeah, Ian, I wasn't talking about the voltage...
Damn, those transformers are monsters. Lift with your knees.
Damn, those transformers are monsters. Lift with your knees.
I build and repair tube amps. http://amps.monkeymatic.com
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Re: HIWATT 400 - any queries?
A couple of pictures as promised - taken with the phone so not fabtastic resolution/quality.
Notes:
Not easily seen - heatshield on top to reflect output tube heat back to rear.
"Military" style build.
Wire colours to tube sockets: yellow are anode connections, blue are cathode, green are grids.
Cheers,
Ian
Notes:
Not easily seen - heatshield on top to reflect output tube heat back to rear.
"Military" style build.
Wire colours to tube sockets: yellow are anode connections, blue are cathode, green are grids.
Cheers,
Ian
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Re: HIWATT 400 - any queries?
Nah dude its part of it I've only worked on one svt though I have a new rule you can't bitch about an amps weight unless your over 80Stevem wrote:Dropped is operative word as they weigh a whole bunch! Do you folks think about getting a extra bench charge for these Amps and SVTs like I do at times?
Re: HIWATT 400 - any queries?
How many hours/days does the owner have to drive into the outback before he gets to someplace where he can crank that thing without someone calling the cops on him?
Re: HIWATT 400 - any queries?
Wow - look at that wiring/layout...
That's how it's done boys & girls.
Mk 3 AVO - melikes much.
I still remember fighting about who got to use the Mk 8 - or the Tektronix 475.
And Ignitron valves with mercury. Fun times.
That's how it's done boys & girls.
Mk 3 AVO - melikes much.
I still remember fighting about who got to use the Mk 8 - or the Tektronix 475.
And Ignitron valves with mercury. Fun times.
Why Aye Man
Re: HIWATT 400 - any queries?
That's beautiful. Like NASA would have wired if there were no weight restrictions for space travel.
I build and repair tube amps. http://amps.monkeymatic.com
Re: HIWATT 400 - any queries?
I was thinking if everything people did was done as heedfully as a vintage Hiwatt, the planet would be all right.
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Re: HIWATT 400 - any queries?
What a beautiful monster
Thanks for posting pics
600V B+ ?
Thanks for posting pics
600V B+ ?
Re: HIWATT 400 - any queries?
It should have a plate voltage ~700V if it's working as designed...That amp is a wet dream.
<b>LF Audioservice</b>
Built:
Weber AB200
Weber 6S100
Hiwatt DR201
Fender 6G3 Deluxe
Built:
Weber AB200
Weber 6S100
Hiwatt DR201
Fender 6G3 Deluxe
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Re: HIWATT 400 - any queries?
I've re-tubed an SVT and I told the owner he was going to have to do the lifting for me. I would help, but he is young and strong, I'm neither.cbass wrote:Nah dude its part of it I've only worked on one svt though I have a new rule you can't bitch about an amps weight unless your over 80
--Jim
"He's like a new set of strings, he just needs to be stretched a bit."
"He's like a new set of strings, he just needs to be stretched a bit."