Welcome to my personal webspace

Knock on the Doors of "Tube-Perception"

the glow of filaments, and invisible valence electrons in motion

making both music and great memories

TFirst door - Hand crafted audio amplifiers


Second door - Classic gear restoration & schematics


Third door - My loudspeakers rants

Fourth door - Tube Amp manifesto "The Una-Tuber"


Fifth door - The Geek Zone


Sixth door - Contact information


Seventh door - Hazard warning/notice


Eighth door - The basics of tube measurement


Ninth door - Hammond/Leslie/Wurlitzer

(Currently under construction)

Tenth door - Schematic Vault

(Currently under construction)

Merlot and Classic Rock, synergy and relaxation

My Audio Power Tubes Opinions

Hi-Fi, Guitar, Bass, Organs & Radios

KT-88/6550 - Cavernous lows & very polite highs, that trash metal crunch, surprisingly good with Horns and Lowthers

KT-66/6L6/5881* - Layered, tonal, great for both HiFi & Guitar Amps, many nice variants, the chameleon of Tone

SPECIAL HONORABLE MENTION IS THE 7355 TUBE* (RIP) - Small 6L6 variant, brilliant design, out of production (eg. Harman Kardon)

KT-77/EL34/6CA7 - Midrange Guitar "screamer", with a nice leading edge, crystal clear HiFi, very nuanced, KT77 smoothest

EL-84/6BQ5 - Musically engaging, great for Classical Music, a smooth operator, vocals are crisp and clean

7591/7591A/7868/6GM5 - Sweet sound, deceivingly smooth at high power, can kill speakers, current production is Russian

7027A (RIP) - Nice Warm & Detailed Sound, used when Tubes roamed the market

8417(RIP) - Audio Power Pentode, late bloomer, akin to a V8 and Oil Price Hikes, long out of production

6F6 Russian (US RIP) - In old Car Radios, absolutely fabulous tonality, a best kept DIY secret, listen here on 16 Ohm PSV-2


6V6/7408 - Lighter version of 6F6 but different sound, filaments are not as hungry as 6F6, can be bright, glassy-clear

6AQ5 (RIP) - Out of production, have a few on hand, will made a prototype amp, with plans to enjoy later

6CM6 - (RIP) also out of production, fantastic Jazz and Vocal, listen... a small 6V6, similar sound character, glassy-clear


E80L/6227 (RIP) - European 9 Pin Pentode. 10,000 hour PQ version, on my short list of Tubes to use, uncommon

2A3 - Single Ended Holography, Fine Bourbon & Single Malt Scotch, look for the Single Plate Sovtek

300B - The trusted voice of pure Class A - the golden S.E. standard - Expen$ive but Musical, used in Preamps as well

Special Mention Power Tube;

6146B - Commonly used for Radio Transmitters, used in Audio Amplifiers, bully of the block. Capable of 100W in PP

My Small Signal Voltage & Gain Stage Tube opinions

Line Stages, Tone Controls, Phase Splitters & Buffers

ECC83/12AX7 - High-Mu, Dual Triode everyone knows something about, it is very common in Audio

ECC81/12AT7 - Medium-Mu Dual Triode, common in Guitar amps, seen less in HiFi amps (Fisher SA300)

ECC82/12AU7 - The true 9 Pin chameleon, Low-Mu, versatile, ubiquitous, handy, the toolbox of small signal tubes

12DW7/7247 - Half of a 12AX7 plus Half of a 12AU7cool tube (Dynaco S35, EICO 2036), nice tube

ECC88/6DJ8/6922 - Frame Grid design, a Love/Hate HiFi reputation, I love'em Hot and Bothered (Audible Illusions)

ECC85 - Used sparingly in Audio, very sweet, much more common in German Amps (Grundig)

EF86/6267 - A small Pentode Tube, everyone needs to listen to, most never have (Mullard 5-20)

6C4 - This is half of a 12AU7, small and petite, very cute, used in Hammond AO-28 Preamp (RIP)

6SN7/5962 - The bulldog of Small Signal Gain Stages, robust and musical (Cary Audio SLP-5)

6J5 - This just half of a 6SN7 (think 6C4), killer tone, a best kept secret, out of production (RIP)

6N7 - Rare metal audio tube, Stromberg Carlson Theater Amps (Stromberg Carlson APH50)

6SL7/5961 - Less seen in amps, Cary Audio used them in the 90's (SE300)

12BH7 - Robust dual triode, awesome & beefy, great good driver tube (Hammond AO-28)

ECC99 - The new kid on the block, speaks with an accent, nouveau 12BH7 (JJ Electronik)

6C45P - A best kept secret for Phono Stages, used in DIY for those in-the-know (Transcendent Sound)

6N1P - More robust than a ECC88/6DJ8, great driver for DHT Triode Tubes (ShermanAudio Kismet)

7199 - Out of production tube (RIP), Pentode/Triode, Russian version so-so (Dynaco ST70)

6AN8 - Out of production tube (RIP), Pentode/Triode (Dynaco MK3, some Japanese Amps)

Tube Rectifiers Review, the music makers

"The unfair reputation"

I hope to launch a Tube Rectifier revival.... QUIET, Shhhhhh, prices will skyrocket.

GZ34/5AR4 - 5V/2A Superman of tube rectifiers, general purpose (Dynaco ST70)

GZ37 - A somewhat filament hungry 5V/2.8A variant of the GZ34, British, rare & expensive

Type 80 Globe - Paleo Rare Tube Rectifier, too much for me as well, for museums

5Z3 - Also rare, museum stuff, not for DIY, unless there is extreme nostagia

5Y3/5Y3GT - Neutral 5V/2A, very reliable when operated within their maximum ratings, quick-on

6X4 - Lighter 6V/.6A version rectifier, mostly used in Preamps (Scott LC21)

5V4 - Rare now, 5V/2A sweetie, nice for medium powered amps 20 to 30w

12X4 - A 12V/0.6A version of a 6X4, same tube, different filament (Dynaco PAS)

6CA4/EZ81 - Like a 6X4, but not as popular, 1amp, think VOX (Leslie Reverb Cabinets)

5U4/5U4G - Robust Rectifier 5V/3A, tall, dark and handsome (US Navy)

5R4GY - That Sexy glass bottle, 5V/3A often seen with Brown Shorts (JAN)

5R4WGB - Potato Masher Rectifier, totally ready for Dinner and Battle (Military Grade)

6AX5/6X5GT - Popular 50's-60's 5V rectifier, similar to 5Y3 in ratings, 5V/0.6A from the 50's

274B - Western Electric, high end tube, available today, must be nice, Expensive as F, $$$

ShermanAudio - Tech Note - SA.TN01 7189 amplifiers

EL84/6BQ5 is not always a substitute for 7189

NEVER replace a 7189 with an EL84/6BQ5 in a 7189 amplifier

Unless the amp was designed for EL-84/6BQ5


If the socket or schematic labels read 6BQ5/EL84/7189

YES both tubes are compatible

If the tube socket is labeled 7189

STOP, you will eventully toast the 7189 amplifier and power tubes

The images above are brrowed from Duncan's Amps

Just an awesome tube website, link below;


7189 Case Study - The Olson AM240

Many of these amps were toasted and roasted by EL84/6BQ5's

A pity I did not take photos of the damage to the Output Transformers

before I discarded them at the local dump

These were charcoal black inside

The Mains Transformer oozed dark resin

A EL84 BBQ with catastrophic consequences

This donor amp gave me a Top Cover and Bottom Plate.


Try Russian 6n14n-EB Tubes, tough as nails

Some cool links to 7189 resources





The Subject Matter Expert Speaks

Mr. Kevin Deal


Direct from the Tube Tabernacle


When great advice is given, certain reactions may manifest

"You are not generally upsetting a Person, you are upsetting their Programming"

The Obligatory "Man Cave" #6

Man Cave #7 Under Construction

Dudes all benefit from a time-out here and there

Forget the Bar's and the Golf Clubs

Put on some Porcupine Tree BluRays...

Personal Guitar Collection (began in the mid 70's)

Giannini GNF-8R CEQ (Brazilian design, crafted in China) needs the bridge piece replaced

 Fender Newporter (Crafted in Japan) plays and sings with 18:1 Grover Tuners, pawn shop buy Roanoke, VA 1996

 Giannini AWN-20 3/4 size (Made in Brazil, my oldest guitar 1974), needs fretwork

 Epiphone Invader Electric (Made in Japan), plan to swap Machine Heads

Fun at 1980's themed Birthday Party

I went as a Europe Band Member

Turn-Key Hangover Service - in Las Vegas

Alcohol is the worst "legal liquid"

Makes for tragedies when incorrectly consumed

Self inflicted pain, nausea and "motor-mouthing"

When you party in Vegas, they have you covered in all aspects

Even Hangovers are no match for the "Hangover Bus"

International Business Travel

Was this pure coincidence or providence?

During my years of random global motion

90% constant travel phase 2000-2015

15 years of filling up passports and adding new pages

GSM, 3GPP, 3GPP2 (RIP) and LMR

I had the honor of meeting a true legend and Master Percussionist

Mr. Billy Cobham

 While attending an L.M. Ericsson business Dinner 

in Panama City, Panama

Listen to "Palindrome" & "Glass Menagerie"

"One Word" from the Mahavishnu Orchestra LP "Birds of Fire", just amazing

Billy's virtuosity and skills, they transcend the ordinary

Billy's playing emanates from somewhere within a parallel universe

Old and New Geek Testaments

Sacred Electrical Theory

Remember always safety first

Prevent fatal electric shocks

& Soldering Iron Burns

Always use Eye Protection

Never work when tired

When measuring, one lead grounded

One hand with probe, other hand in pocket

My general Bio and Tube Story

"From Tuba to Tubes"

Born on Urantia (Earth)


Puerto Rico (Borinquen) - 60's-80's

Xmas Concert, Sousaphone - 72

Gianinni AWN-20 3/4 Student Guitar - 75

High School Jazz Band, Electric Bass  - 78-79

Arian Music Award Recipient 79 & 80

Antilles Pirate A.H.S. - Class of 80

 AHS Varsity Soccer #4 1977-1979

Coached by the best Math Teacher ever - Mr. Paul Trittschuh

The Quaternians


To the left, my first Vacuum Tube Amplifier - late 1972 (Photo in 73-74)

The LP spinning - Elton John's Greatest Hits Vol.1

The age of Alice Cooper, The Who, Black Sabbath and Led Zeppelin

Tube Amp pulled out of Dictograph 100A Mono Console

 a hand-me-down gift from Mr. Beck

Thank you so much Mr. Beck

You launched me on this journey

100A Console and internal Tube Amplifier

From Radio Museum Website (thank you!)



B.S.E.E. - Class of '86

Electrical Engineering

Month's out of College

Motorola Site Survey Work 1987

Radio Systems support, late 80's

 Cool High Voltage "Hockey-Puck" EIMAC Tubes

Microwave Transmitters +1250 Volts DC on the Plates

The tube cage had an "interlock" plug, to avoid shocks

Legacy 1962 Lenkurt Microtel 76A Microwave Radio (2 GHz)

The MW system was as old as I was, yellowing Service Manuals

by turning pages they would rip apart

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