Pair Of Mullard M8137 CV4004 KB/D. Condition of these items looks to be good. I am unable to test so they are sold as seen. For exact international shipping costs please contact me.

Mullard M8137 ECC83 CV4004 Box plates Halo getter Tested on AVO CT160 Ia: 1.9 & 1.9Gm: 1.9 & 2.1 The cardboard box has been repurposed. Shipping Please contact me for a postage quotation to your country before paying. Any questions, please ask. No shipping to Russia. Before paying please wait for an invoice or ask for a postage quotation.

My Ref: (V-1044) Mullard M8137 ECC83 Valve Tested fine on my PAC912 tester Unboxed Combined postal discount given

I have 4 super rare very strong tv7 tested Mullard box plate M8137 / CV4004 / 12AX7 tubes

RARE STRONG MULLARD M8137 CV4004 ECC83 NOS UNBOXED WITH CODE 641 R3C4 FROM MARCH 1973 IN SUPERB CONDITION AND PERFECT WORKING ORDER - TESTED STRONG ??AVO VCM163 TESTED READINGS TUBE 1 - Ia 1.5/1.5 gm 1.7/1.7 100% = Ia 1.2 gm 1.6 ?

I have 4 super rare very strong tv7 tested Mullard box plate M8137 / CV4004 / 12AX7 tubes

MULLARD VALVE M8137 CV4004 white print made in Great Britain date / factory codes-- looks like 641R1G1

MULLARD Valve M8137 CV4004 boxed new old stock made in Great Britain KB/D date and factory codes are not very clear looks like -- 64.1 R3D2

RARE STRONG MATCHED PAIR OF MULLARD M8137 CV4004 ECC83 PRINT WORN BUT CODES VISIBLE DATED TO 1965 AND 1967 IN GOOD CONDITION AND PERFECT WORKING ORDER - TESTED STRONG ??AVO VCM163 TESTED READINGS TUBE 1 - Ia 1.4/1.3 gm 1.6/1.7 TUBE 2 - Ia 1.9/1.7 gm 1.8/1.7 100% = Ia 1.2 gm 1.6 ? PLEASE SEE MY OTHER AUCTIONS ?

Mullard M8137 CV4004 KB/D. Condition of this item looks good. I am unable to test, so it’s sold as seen. For exact international postage rates, please contact me.

WELCOME TO YET ANOTHER GREAT DR-TRON AUCTION. THIS SALE IS FOR A VINTAGE VALVE TUBE..... Mullard M8137, CV4004, ECC83 / 12AX7CV4004 KB/D. WHITE PRINT.HALO GETTER. Box Anode plates. MADE IN Great Britain. Code = 641-R8G4.TESTS 100%..A1 = 1.90mA. A2 = 1.75mA..... 100% = 1.2mA.FROM WORKING EQUIPMENT. Please note...... ALL MY TUBES ARE TESTED ON MY CALIBRATED ...... AVO VCM-163 TUBE TESTER .... BEAR IN MIND ALL TUBE TESTERS GIVE SLIGHTLY DIFFERENT READINGS..... MY READINGS ARE ACCURATE AND HONEST. I WILL SHIP THIS ITEM WORLDWIDE. PLEASE LOOK AT MY OTHER VINTAGE PARTS AUCTIONS. THANK YOU FOR TAKING TIME TO VIEW MY ITEM, AND GOOD LUCK !!!

2x Mullard ECC83 Valves Date Code: I61 B2H2, I61 B2H2 Tested by AVO VCM Tester Valve 1 Ia1 = 0.85(mA), gm1 = 1.3(mA/V) Ia2 = 1.05(mA), gm2 = 1.4(mA/V) Valve 2 Ia1 = 1.02(mA), gm1 = 1.45(mA/V) Ia2 = 0.8(mA), gm2 = 1.3(mA/V) NOS specification: Ia = 1.2(mA), gm = 1.6(mA/V) *** This valve has also been tested in amplifier without any noise. *** Postage Costs I am happy to post this item to worldwide and combine postage cost on multiple purchases. 20230522L017

2x Mullard 12AX7S/CV4004 Valves This pair of 12AX7S/CV4004 are with very unique box-anode construction. They are believed manufactured by Mullard Mitcham factory Tested by AVO VCM Tester Valve 1 Ia1 = 0.7(mA), gm1 = 1.25(mA/V) Ia2 = 0.8(mA), gm2 = 1.3(mA/V) Valve 2 Ia1 = 0.78(mA), gm1 = 1.3(mA/V) Ia2 = 0.8(mA), gm2 = 1.35(mA/V) NOS specification: Ia = 1.2(mA), gm = 1.6(mA/V) *** This valve has also been tested in amplifier without any noise. *** Postage Costs I am happy to post this item to worldwide and combine postage cost on multiple purchases. 20230522L004

2x Mullard ECC83 Valves Very rare pair of Mullard ECC83 manufactured in 1955 with long-plate and []-getter Date Code: mC1 B5F, mC1 B5F Tested by AVO VCM Tester Valve 1 Ia1 = 1.32(mA), gm1 = 1.55(mA/V) Ia2 = 1.45(mA), gm2 = 1.4(mA/V) Valve 2 Ia1 = 1.23(mA), gm1 = 1.5(mA/V) Ia2 = 1.48(mA), gm2 = 1.45(mA/V) NOS specification: Ia = 1.2(mA), gm = 1.6(mA/V) *** This valve has also been tested in amplifier without any noise. *** Postage Costs I am happy to post this item to worldwide and combine postage cost on multiple purchases. 20230522L001

2x Siemens ECC83 Valves Date Code: ?W mCP, *** ** Branded Mazda and Mullard but manufactured by Siemens Halske. Tested by AVO VCM Tester Valve 1 Ia1 = 0.95(mA), gm1 = 1.35(mA/V) Ia2 = 1(mA), gm2 = 1.4(mA/V) Valve 2 Ia1 = 0.95(mA), gm1 = 1.35(mA/V) Ia2 = 1.03(mA), gm2 = 1.4(mA/V) NOS specification: Ia = 1.2(mA), gm = 1.6(mA/V) *** This valve has also been tested in amplifier without any noise. *** Postage Costs I am happy to post this item to worldwide and combine postage cost on multiple purchases. 20220412L023

3x MONITOR 12AX7/ECC83 Valves Made in Holland Tested by AVO VCM Tester Valve 1 Ia1 = 0.9(mA), gm1 = 1.4(mA/V) Ia2 = 0.95(mA), gm2 = 1.45(mA/V) Valve 2 Ia1 = 0.98(mA), gm1 = 1.55(mA/V) Ia2 = 0.93(mA), gm2 = 1.5(mA/V) Valve 3 Ia1 = 1.2(mA), gm1 = 1.5(mA/V) Ia2 = 1.38(mA), gm2 = 1.6(mA/V) NOS specification: Ia = 1.2(mA), gm = 1.6(mA/V) *** This valve has also been tested in amplifier without any noise. *** Postage Costs I am happy to post this item to worldwide and combine postage cost on multiple purchases. 20220412L005

1x VALVO ECC83 Valve Date Code: mCP DX Very rare ECC83 munfactured by VALVO (Germany) with long plate and inclined D-getter Tested by AVO Mark VCM tester Ia1 = 1.3(mA), gm1 = 1.6(mA/V) Ia2 = 1.35(mA), gm2 = 1.65(mA/V) NOS specification: Ia = 1.2(mA), gm = 1.6(mA/V) *** This valve has also been tested in amplifier without any noise. *** Postage Costs I am happy to post this item to worldwide and combine postage cost on multiple purchases. 20210507L030

2x BRIMAR 12AX7 Valves Date Code: 4F2 (1952), 3J2(1952) Early version of BRIMAR 12AX7 with long black plate and []-getter Tested by AVO VCM Tester Valve 1 Ia1 = 0.91(mA), gm1 = 1.6(mA/V) Ia2 = 1.15(mA), gm2 = 1.8(mA/V) Valve 2 Ia1 = 0.96(mA), gm1 = 1.65(mA/V) Ia2 = 1.03(mA), gm2 = 1.8(mA/V) NOS specification: Ia = 1.2(mA), gm = 1.6(mA/V) *** This valve has also been tested in amplifier without any noise. *** Postage Costs I am happy to post this item to worldwide and combine postage cost on multiple purchases. 20221122L001

5x TUNG-SOL ECC83 Valves Manufactured in 1963. Tested by AVO VCM Tester *** This valve has also been tested in amplifier without any noise. *** Postage Costs I am happy to post this item to worldwide and combine postage cost on multiple purchases. 20220412L027

1x LORENZ/Holland ECC83 Valve Date Code: *** ?1G1 Rare dimple disc version manufactured in Holland, great sounding ECC83. Tested by AVO VCM Tester Ia1 = 1.2(mA), gm1 = 1.75(mA/V) Ia2 = 1.15(mA), gm2 = 1.7(mA/V) NOS specification: Ia = 1.2(mA), gm = 1.6(mA/V) *** This valve has also been tested in amplifier without any noise. *** Postage Costs I am happy to post this item to worldwide and combine postage cost on multiple purchases. 20220828L009

2x Mullard ECC83 Valves Date Code: I61 B3B4, I61 **** Yellow pirnt, copper-grid-support, and halo-getter Tested by AVO VCM Tester Valve 1 Ia1 = 0.85(mA), gm1 = 1.5(mA/V) Ia2 = 2(mA), gm2 = 1.8(mA/V) Valve 2 Ia1 = 1.55(mA), gm1 = 1.7(mA/V) Ia2 = 1.3(mA), gm2 = 1.5(mA/V) NOS specification: Ia = 1.2(mA), gm = 1.6(mA/V) *** This valve has also been tested in amplifier without any noise. *** Postage Costs I am happy to post this item to worldwide and combine postage cost on multiple purchases. 20221122L016

For your consideration are two Mullard M8137 cv4004 with matching date codes. These are the military versions of Mullards 12AX7/ECC83 These tubes were tested in a Hickok 539C where the minimum reading is 875gm and the reading for a new tube is 1375gm. The tubes tested at 1600gm/1500GM & 1600gm/1600gm

1x Mullard CV492 Valve Very rare Mullard CV492/ECC83 with long plate and []-getter, new in original box Date Code: mC1 B6H (1956) Tested by AVO VCM Tester Ia1 = 1.58(mA), gm1 = 1.9(mA/V) Ia2 = 1.43(mA), gm2 = 1.7(mA/V) NOS specification: Ia = 1.2(mA), gm = 1.6(mA/V) *** This valve has also been tested in amplifier without any noise. *** Postage Costs I am happy to post this item to worldwide and combine postage cost on multiple purchases. 20230522L020

PHILIPS 12AX7 ECC83 CV492 M8137 CV4004 B339RARE UN-USED Valve, Made in Holland 1950sNEW OLD STOCK NEVER USED (I wish I had more of these)D Getter Tested at an incredible Ia = 1.2A / 1.2A @ gm = 1.8mA/V / 1.9mA/V I couldnt believe it so I took Photos! HAD TO OPEN THE BOX TO TEST IT.