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Old 1st February 2007, 08:08 PM   #1
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Default Upgrading a Beard P100 tubeamp

Hi,
After many year of service, I am upgrading my Beard P100 power amp. I will be installing ClarityCap SA series 0.1uF bypass capacitors on the power suply of both channels and will be replacing the DC coupling caps between the tube amplification stages to ClarityCap SA series caps. One issue I have is that the capacitors between the first and second amplification stage is 0.022uF. I could not find a ClarityCap SA of the same value. Can I replace the 0.022uF caps with 0.1uF caps instead. What would be the effect of such a change?

Are there any other changes you would recomend?

thanks
Ronen
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Old 1st February 2007, 08:28 PM   #2
poynton is offline poynton  United Kingdom
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Hi.

Do you have a circuit for the P100 ?

I bought mine some years ago, second-hand from a local Hifi shop.
A bargain !! I replaced 1 KT88 to get it going .

Like yours, it is probably in need of some TLC.


Andy
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Old 4th February 2007, 06:07 PM   #3
poynton is offline poynton  United Kingdom
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Default Re: Upgrading a Beard P100 tubeamp

Quote:
Originally posted by ronenash
Hi,
After many year of service, I am upgrading my Beard P100 power amp. I will be installing ClarityCap SA series 0.1uF bypass capacitors on the power suply of both channels and will be replacing the DC coupling caps between the tube amplification stages to ClarityCap SA series caps. One issue I have is that the capacitors between the first and second amplification stage is 0.022uF. I could not find a ClarityCap SA of the same value. Can I replace the 0.022uF caps with 0.1uF caps instead. What would be the effect of such a change?

Are there any other changes you would recomend?

thanks
Ronen
With regard to bypass capacitors, there is a current thread on the forum with opinion divided as to whether this is a good thing. My advice would be 'Try it and see if it changes things for the better!'

Changing the values of the caps from 0.022 to 0.1uF will alter the LF rolloff point but will do no harm.

Ideally, you should check and replace all components that are outside the original spec. or are showing signs of aging.

Andy
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Old 2nd June 2007, 03:34 PM   #4
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Default Beard P100

Hello I have recently purchsed a Beard P100 power amplifier, does anyone know the correct valve order. Looking from the front (beard P100 logo infront of you) to back of the amplifier I have e82cc on the left and right sides. Then I have e81cc on the left and e83cc on the right in the second row, and on the third row I have e83cc on the left and e81cc on the right? then the Kt88 after. Does anyone know which is the correct order. Below is the order of my valves at the moment

KT88 KT88
KT88 KT88
e83cc e81cc
e81cc e83cc
e82cc e82cc

If anyone has a manual or ideally schematic could they send it to me please.
Also does anyone know what the two variable resistors are for on the inside of the amplifier by 33uF capacitor and the preamp valves on the PCB are for, and what upgrades would you recommend.
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Old 22nd June 2007, 09:39 AM   #5
traf is offline traf  United Kingdom
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Craig

Did you ever receive the schematic I emailed you? If not get back in touch.

The two VRs balance the current flowing on each side of the push/pull circuit. Simply adjust such that there is 0V across it.

From a now ex- Beard P100, P101, P505 and CA506 owner

Simon
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Old 22nd June 2007, 10:27 AM   #6
poynton is offline poynton  United Kingdom
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Quote:
Originally posted by traf
Craig

Did you ever receive the schematic I emailed you? If not get back in touch.

The two VRs balance the current flowing on each side of the push/pull circuit. Simply adjust such that there is 0V across it.

From a now ex- Beard P100, P101, P505 and CA506 owner

Simon

Simon,

Please could you mail me a copy of the schematic.

I did request a copy from RONENASH but never received it.

Andy
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Old 22nd June 2007, 01:58 PM   #7
traf is offline traf  United Kingdom
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Can't email being a lowly newbie

But I can hopefully attach the files

Part 1:
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File Type: gif gifbeard1.gif (67.6 KB, 890 views)
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Old 22nd June 2007, 01:58 PM   #8
traf is offline traf  United Kingdom
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Part 2:


Note there is an error in the V3 stage. If noone spots it I can elaborate but it should be fairly obvious.
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File Type: gif beardmk2finishedgif.gif (63.7 KB, 851 views)
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Old 22nd June 2007, 02:34 PM   #9
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Valve V3B is on holiday.
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Old 9th October 2007, 06:12 AM   #10
cocosal is offline cocosal  Uruguay
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Hello, Im owner Beard P505 MKII preamplifier. I need replace the tubes. Are you the schematic of this preamp? Types of nine valves?

sorry but my english is poor

Thanks
Ruben
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