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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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Thread Tools |
12th Jul 2019, 8:10 pm | #41 |
Triode
Join Date: May 2016
Location: Cannock, Staffordshire, UK.
Posts: 41
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Re: Hacker GP42 and AL42 restoration help
Ok Frank i will change what Michael advises and do a re check
Many thanks |
12th Jul 2019, 8:26 pm | #42 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,427
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Re: Hacker GP42 and AL42 restoration help
If you still have voltages that are a long way out after replacements are fitted. You could measure the cathode voltages of the pentodes, they are 1.4v and 4v at present. Swop the valves over, if the low voltages follow the valve then it’s a sign that the valves are low emission.
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Frank |
12th Jul 2019, 9:20 pm | #43 |
Triode
Join Date: May 2016
Location: Cannock, Staffordshire, UK.
Posts: 41
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Re: Hacker GP42 and AL42 restoration help
Hi Frank connected speaker and plug for stylus and checked voltages again this is what i got compared to last readings
HT1 C12 286V HT2 C11 272V HT3 C8 248V V1A PIN9 164V V2A PIN9 120V V1B PIN6 265V V2B PIN6 265V V1A PIN2 0V V2A PIN2 0V V1B PIN 7 7.1V V2B PIN7 7.2V |
12th Jul 2019, 10:10 pm | #44 |
Triode
Join Date: May 2016
Location: Cannock, Staffordshire, UK.
Posts: 41
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Re: Hacker GP42 and AL42 restoration help
Voltages G3 = 257v on both
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12th Jul 2019, 10:14 pm | #45 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,427
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Re: Hacker GP42 and AL42 restoration help
Those look more like they should do, have you changed any components but I would have expected pin 2 to have about 1v on them. The Pentode cathodes are about right so the emission is ok.
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Frank |
12th Jul 2019, 10:17 pm | #46 |
Triode
Join Date: May 2016
Location: Cannock, Staffordshire, UK.
Posts: 41
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Re: Hacker GP42 and AL42 restoration help
No all i have done is connect the speaker
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12th Jul 2019, 10:18 pm | #47 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,427
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Re: Hacker GP42 and AL42 restoration help
So the voltages you took before were without the speaker or dummy load?
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Frank |
12th Jul 2019, 10:19 pm | #48 |
Triode
Join Date: May 2016
Location: Cannock, Staffordshire, UK.
Posts: 41
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Re: Hacker GP42 and AL42 restoration help
Yes
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12th Jul 2019, 10:21 pm | #49 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,427
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Re: Hacker GP42 and AL42 restoration help
Oh well you will know for the future, the amplifier was probably going unstable.
So back to the problem, check those components that Micheal suggested.
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Frank |
12th Jul 2019, 10:24 pm | #50 |
Triode
Join Date: May 2016
Location: Cannock, Staffordshire, UK.
Posts: 41
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Re: Hacker GP42 and AL42 restoration help
Ok thanks will do
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14th Jul 2019, 6:48 pm | #51 |
Rest in Peace
Join Date: Mar 2006
Location: N.W. Oxfordshire(Chipping Norton)
Posts: 7,306
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Re: Hacker GP42 and AL42 restoration help
Incidentally a valve amplifier should never be run without either a loudspeaker or equivalent dummy load connected
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21st Jul 2019, 10:12 pm | #52 |
Triode
Join Date: May 2016
Location: Cannock, Staffordshire, UK.
Posts: 41
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Re: Hacker GP42 and AL42 restoration help
Thanks for that livewire advice taken
Can anyone point me in the right direction for replacement rexine for the gondolier gp42 lid thanks |
23rd Jul 2019, 9:20 pm | #53 |
Hexode
Join Date: Dec 2018
Location: Sheffield, South Yorkshire, UK.
Posts: 364
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Re: Hacker GP42 and AL42 restoration help
you wont get either of the 2 colours that Hacker used
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27th Jul 2019, 9:51 pm | #54 |
Triode
Join Date: May 2016
Location: Cannock, Staffordshire, UK.
Posts: 41
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Re: Hacker GP42 and AL42 restoration help
ok thanks brassbits i did have a look and like you said i dont think i will get any
thanks for replying |
28th Jul 2019, 12:11 pm | #55 |
Heptode
Join Date: May 2015
Location: Reading, Berkshire, UK.
Posts: 692
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Re: Hacker GP42 and AL42 restoration help
Hello can I ask why you want to replace the rexine on the lid, for example is it torn or frayed, or has it just discoulered/faded?
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2nd Aug 2019, 10:09 pm | #56 |
Triode
Join Date: May 2016
Location: Cannock, Staffordshire, UK.
Posts: 41
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Re: Hacker GP42 and AL42 restoration help
Hi leslie i have a few woodworm holes in the lid
I have treated the casing with woodworm killer |
3rd Aug 2019, 8:58 am | #57 |
Dekatron
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
Posts: 8,302
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Re: Hacker GP42 and AL42 restoration help
With patience these (pre-treated) holes can be filled. If you use a hard soap like Imperial Leather (which comes in 2 colour shades) slightly soften it in warm water and then just rub this over the affected area. Any surplus can be skimmed off using the edge of a Stanley knife blade. It will then harden. All this may sound a bit fastidious I know, but it really does improve the appearence.
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Edward. |
6th Aug 2019, 9:59 pm | #58 |
Triode
Join Date: May 2016
Location: Cannock, Staffordshire, UK.
Posts: 41
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Re: Hacker GP42 and AL42 restoration help
Thank you Edward i will give that a go
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14th Aug 2019, 5:07 pm | #59 |
Triode
Join Date: May 2016
Location: Cannock, Staffordshire, UK.
Posts: 41
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Re: Hacker GP42 and AL42 restoration help
Good afternoon everyone i just need a bit of advice on my 2 amps the one out of the gondolier and the one out of the al41
The amp in the gondolier has had the capacitors and resistors changed as advised by Michael Maurice and the other amp is untouched The amp that has had the changes when all is connected back I have got a loud hum when the volume is turned up Voltage across r6 is 78v and r7 is 113v on gp42 Voltage on untouched amp is r6 120v and r7 91v Any help and advice will be greatly apprecciated thankyou |
14th Aug 2019, 10:11 pm | #60 |
Triode
Join Date: May 2016
Location: Cannock, Staffordshire, UK.
Posts: 41
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Re: Hacker GP42 and AL42 restoration help
Hi all just anofher problem i put every thing back together plugged in the turntable and no power to turntable advice needed please
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