PEARL's Audio Note Series and Literature Archive


The Audio Note Series


AN 0.3

  The Index to the PEARL Vacuum Tube Technology Archive
Note that this document is updated approximately monthly as new items are uploaded to our site. All downloads presently available can be accessed through the PEARL Archive listings below.

150 KB


AN 0.4

  Vacuum Tube Electronics: A Review of the Major Texts:
Scott authoritatively reviews scores of the classic textbooks on vacuum tube theory, implementation, construction and so on . . . . highly recommended. Presented here with the permission of
Scott Frankland.

298 KB


AN 1.3

  PEARL Tube Coolers:
The 198 pg. PEARL Audio Note, “PEARL Tube Coolers and Equipment Reliability” provides both a present-day overview and several magazine reviews as well as an extensive overview of the period literature and patents.

14 MB


AN 1.5

  PEARL Tube Coolers - A Quick Start Guide:
A 4 page guide to the basic theory of operation and installation of our tube coolers

1 MB


AN 2.1.1

  A Little Input on Audio Output Transformers & Update:
Some basic transformer theory and specifications on PEARL's high power, ultra-wide bandwidth output transformers.
The Update covers ultra-linear operation implemented with a separate screen winding and regulated, screen power supply.

151 KB


AN 6.2

  Getting the Shake and Rattle Out of Your Rock and Roll: Suppressing Microphonic Output from Vacuum Tube Gear -
Information on microphony in general and PEARL Iso-sockets in particular.

76 KB


AN 7.1

  Iso-socket Installation Instructions:
The title says it all . . .

1 MB


AN 8.1

  The Measurement of Microphonic Effects in Vacuum Tubes:
A very informative discussion of microphony

68 KB


AN 9.1

  Making Contact with Your Tubes:
How to clean the heavy oxides from through-glass pins of tubes using same for connection with socket contacts.

60 KB


AN 23.1

  The PEARL SC 280 Monoblock - Notes on a Work in Progress:
Although the title does say it all, these notes were written in 1990/2 and although much work has been done since then, no notes documenting that work have been written as yet.

232 KB


AN 23.2

  The PEARL SC 280 Monoblock - Notes on a Work in Progress:
This is an Update to AN 23.1

356 KB










Download the index to the PEARL Vacuum Tube Technology Archive

150 KB

Volume 1 - Power Amplifiers

  Sec. 01   Amplifier Basics - 15 articles

Sec. 01

  Sec. 02   Ultra-linear Amplifiers - 23 articles

Sec. 02

  Sec. 03   Mcintosh Unity-coupled Amplifier

Sec. 03

  Sec. 04   Triode Connected Tetrodes

Sec. 04

  Sec. 05   Constant Current Output Stages

Sec. 05

  Sec. 06   The Williamson Amplifier

Sec. 06



Volume 2 - Power Amplifiers

Sec. 07    

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  Sec. 09    

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  Sec. 10    

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  Sec. 11    

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  Sec. 12    

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  Sec. 13    

Sec. 13



  This page is posted as something of a precursor to the construction of our site. Here we've made available a number of PDF files that will eventually be available from our site's main navigation page(s). In the meantime, and so that those viewing posts archived on various list servers will find live links in the future we will keep this page as permanent resource.