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Old 16th July 2002, 04:45 PM   #121
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Default Breaking in JLH for ESL

I'll call this 2002 JLH 15W Class A.

Just finished, bias at 3.2A, no DC offset problem, after 2 hours power on the DC measured at output is -0.1mV on one channel and -1.2mV on the other. Transformer gets rather hot.
Initial impression of sound quality compare with my dismantled 1996 JLH; When listen to the Shefield Lab test CD, big improvements. Other cds the bass is very detail and solid, especially those quiet/distant recorded drums do not get smear by the main loud passage. But the vocal does not have the tube sound like voice as my previous 1996 JLH. The top end/ high frequency is getter more open up/ dynamic everyday pass. It's been only 15 hours listening time so far.

Chris
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Old 26th August 2002, 07:17 PM   #122
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Default Iq setting for JLH for ESL

JLH for ESL (2002 JLH)

This amp sound much better when Iq is set at 4A.

Chris
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Old 26th August 2002, 08:21 PM   #123
paulb is offline paulb  Canada
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160 watts of power dissipation per channel? What are you using for heatsinks?
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Old 27th August 2002, 07:10 AM   #124
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Dear all ....

Sorry if I'm wrong ... but if I mirroring the JLH schematic, I get the Hiraga amp .....

regards:
ragil.hastomo
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Old 27th August 2002, 11:44 AM   #125
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Default Heatsink?

Quote:
160 watts of power dissipation per channel? What are you using for heatsinks?
I bought the heatsinks from RScomponent (UK) part number 401-958. A dozen of them is needed.
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Old 28th August 2002, 10:18 PM   #126
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Default heatsink?

um...four (or eight) output devices, twelve heatsinks?
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Old 29th August 2002, 04:30 AM   #127
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Default 4 + 4 + 2 + 2 = 12

There are two voltage regulators per PSU need to be mounted on heatsinks too..that's why I guess..
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Old 6th October 2002, 06:22 PM   #128
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JLH 2002 , still waiting for inspiration for the faceplate
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Old 6th October 2002, 06:29 PM   #129
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Default Full of it vessels, plenty

Face plate removed, the pcb in the front is the soft start circuit, does not work yet, capacitor as resistor value is too high so the relays are not working without power. Too scare to ask basic questions in this forum, too many full of it around, ops, forget to keep quiet, sorry.
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Old 6th October 2002, 06:50 PM   #130
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Default Keeping me warm at night

This is where I heat them up between the 61" Sony
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