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AccessoriesValves Guides - Mesa Boogie
Mesa Boogie valve Reference Guide
The purpose of our Mesa Boogie valve reference guide is to enable Mesa owners to identify the valves in their amplifiers.This section gives you clear pictures of the valves used by Mesa Boogie both past and present. This is a pure reference section to enable you to recognise the valves that would have come in your amplifier when new. We have detailed the factory that produced these valves in order to help you order valves from the same factory.
Mesa ECC81/12AT7
Mesa ECC81/ 12AT7 is made at the Chinese Factory and is mainly used as a reverb driver and phase splitter in some Mesa amplifiers.
The ECC81 has not undergone the changes and improvements that the ECC83/12AX7 has had over recent years.
We have found that most New old Stock items from Mullard, G.E, Philips and the German made Harma ECC81 out perform this item in both these applications and would be our recommendation.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Mesa ECC83/12AX7-SPAX
Mesa ECC83/ 12AX7-SPAX is made at the Russian reflector factory. This valve is used in the first positions where low noise and low microphonics are the requirements. The Mesa SPAX has a rubber cap on the valve in order to reduce the microphonics, hence the apperence is different.
The Harma 7025 DR-250 is exactly the same valve and selected for use in Mesa amplifiers. Harma ECC83-STR is also a good choice as this is lower gain and produces warmer sound.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Mesa ECC83/12AX7-R2
Mesa ECC83/ 12AX7-R-2 is made at the Russian reflector factory and has been used by Mesa as the standard stock 12AX7 in all Mesa produced over the last 7 years.
The valve is high gain and produces a clear and even response. The Harma 7025 DR-250 is exactly the same valve and is selected for use in Mesa amplifiers. Harma ECC83-STR is also a good choice as this is lower gain and produces warmer sound.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Mesa 6L6GC/5881 STR-425
Mesa 6L6GC/5881 STR-425 was the original Russian military valve produced by the reflector factory. This valve is very reliable and produces a round sound with recessed treble but really lacks the sonics of most of all the modern 6L6GC that were produced after it.
The 5881 works well in taming over bright amplifiers and produces a tight if what midrange pronounced sound.
We have early N.O.S military reflector 5881 the same as Mesa used in the late 1980 early 1990's.So if you want the same valve then you need to order the Harma 5881.
Upgrades would be the Winged C Svetlana 6L6GC, Harma 6L6GC-STR, Harma 6L6GC-retro which we have in special selected sets for Mesa amplifiers.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Mesa 6L6GC STR-427
Mesa 6L6GC-STR 427 was one of the first Chinese 6L6GC. The sides have two mica spacers at the top of the glass which is easily seen in the photo and helps us identify this valve. This item has long been discontinued by Mesa. The main reason for this was the improvements the Chinese factory made to standard design. Mesa then introduced the 6L6GC-STR 440 which is the improved Chinese design.
The new Chinese item distorts very quickly with a one dimensional sound when compared to other 6L6GC that are on the market. Indeed most of the current production 6L6GC on the market still outperforms the new Chinese item. If your amp is fitted with 6L6GC STR-427 or STR 440 and you wish to keep the same sound then you need to order the T.A.D 6L6GC-STR.
Upgrades would be the Winged C Svetlana 6L6GC, Harma 6L6GC-STR, Harma 6L6GC-Retro which we have in special selected sets for Mesa amplifiers.
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PLEASE NOTE we do not stock this valve,
This is for visual reference only.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Mesa 6L6GC STR-430
The Mesa STR-430 is the same valve as the Sovtek 6L6WXT plus and 6L6GC-Electro Harmonix.
The Sovtek 6L6GC- EH is the impoved version of the Sovtek 6L6WXT plus.The the EH version is more linear and handles higher plate
better but is basically the same valve.
In my experience in our recent tests both the winged C Svetlana 6L6GC and Harma 6L6GC-STR offer sonic improvements over the Sovtek items and these would be my choice. If you want the same item as this then order the Sovtek/Electro Harmonix 6L6GC-EH we have these is selected sets for Mesa boogie.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Mesa 6L6GC STR-440
Mesa 6L6GC STR-440 is the latest 6L6GC from the Chinese factory.
This valve replaced the STR-427 as the Chinese made improvements to the valves high voltage stability and sonic clarity.
The valve distorts very easily when driven at moderate levels. This makes it a good valve for blues but it lacks the character and definition of the Winged C Svetlana 6L6GC, Harma 6L6GC-STR
If you want exactly the same valve as the STR-440 then you will need to order the T.A.D 6L6GC-STR.
Upgrades would be the Winged C Svetlana 6L6GC, Harma 6L6GC-STR, Harma 6L6GC-retro which we have in special selected sets for Mesa amplifiers.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Mesa 6L6GC STR-454
Mesa 6L6GC-STR-454 is the original Winged C Svetlana 6L6GC. The way to tell this valve is the two flying saucer looking getters at the top of the valve.
In all the tests I have run the 6L6GC winged C has always performed extremly well.
The Sound character is very detailed and even with tight low end and shimmering highs.
If you want the same item as this then you need to order the Wingded C Svetlana 6L6GC from us which we have in special selected sets for Mesa.
The Harma 6L6GC-STR offers a quicker distortion, Harma 6L6GC-retro offer a harder more aggresive sound but these are just differences. The svetlana is an excellent valve in any Mesa.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Mesa 6V6GTA STR-417
Mesa 6V6GTA STR-417 is made in the Chinese factory. Improvements have been made by the Chinese factory over recent years to this design. It still falls short in sound quality terms when compared to New old stock items From Brimar,Philips and G.E.
We stock this item as the 6V6GT by T.A.D but my recommendation out of the modern produced 6V6GT would be the JJ/Tesla item if you cannot run to original U.S.A 6V6GT.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Mesa EL34 STR-442
Mesa EL34 STR-442 is the Original Svetlana made in Russia.
This is known by most of us as the Svetlana Winged C EL34. This valve you can identify by the small fying saucer style ring on the getter and the smooth non stapled anode plate.
The Svetlana produces a rich smooth overdrive sound with plently of detail and control. This valve performs excellently on all musical styles.
So if you want the same item then you need to order the EL34 Svetlana winged C or our EL34 1999-2000 production which are new old stock Svetlana with the original S logo.Mesa EL34 STR-447
Mesa EL34 STR-447 is made by Sovtek in Russia.
This is known by most of us as the Sovtek EL34 Electro harmonix.
The Sovtek produces a hard and aggressive sound in Mesa which will be to many Rock players taste.So if you want the same item then you need to order the EL34 Electro Harmonix from us.
Upgrades can be made by using the winged C Svetlana EL34, Harma E34L-STR, JJ/Tesla E34L .
The Harma EL34-Retro proved to give a Aggresive edge but with more punch and top end clarity than the Sovtek/EH type and would be my recommendation for Grunge/Metal players.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
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Mesa EL34 STR-450 NOS
Mesa EL34 STR-450 is the original New old stock valve made in the East German RFT factory.
This is known by most of us as the Siemens EL34.
The Siemens/RFT valve is a classic valve than is non longer in production. Very popular in America as it has a very clear top end response and has early compression.
The Siemens/RFT is a tough act to follow and no valve matches the Siemens/RFT for it trademark character clear top end sound.
Two Alternatives with extended top end are Harma E34L-STR and JJ/Tesla E34L.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Mesa EL84
The Mesa EL84 is made at the reflector factory in Russia. This valve is known by most of us as the Sovtek EL84. The Original reflector valves had the Russian 6n14 designation.
To upgrade this valve the Harma E84L is a better sounding Military valve, The JJ/Tesla and Sovteks higher gain EL84 EH.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Mesa 5U4G
Mesa 5U4G with the brown base is made in China. Mesa also used the Russian 5U4G which was old military stock made ny the Svetlana factory which had a black base.
Mesa now use the smaller bottle 5U4GB in current production amps.
We can supply original Military Russian 5U4G Harma or Svetlana or original U.S.A made 5U4GB by Amperex and National which are fully interchangeable and offer greater clarity.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Mesa 5U4GB
Mesa 5U4GB is made by Sovtek and is the 5U4GB Electro Harmonix. The Russian rectifier valve has proved very reliable. The 5U4GB is fully interchanable with the large bottle 5U4G.
Mesa now use the smaller bottle 5U4GB in current production amps.
We can supply original Military Russian 5U4G Harma or Svetlana or original U.S.A made 5U4GB by Amperex and National which are fully interchangeable and offer more clarity.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
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Mesa GZ34/5AR4
Mesa GZ34/5AR4 is made in China and currently not used in any current production amplifier .
The Sovtek GZ34 or the Harma GZ34 would be my choice as both have very proved to be very reliable over a period of many years.
The GZ34 will give more clarity in your dual or triple rectifier as they produce less voltage drop (SAG) when used to replace the 5U4G OR 5U4GB.This give the amplifier a cleaner less muddy sound.
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PLEASE NOTE we do not stock this valve,
this is for visual reference only.
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