octal power tubes EL34, E34L, 6CA7, KT77, 6P27C, EL34-2 Unless otherwise specified, these are matched in-house at BTB with an anode voltage of 450 volts
EL 34B RSD - EL34B RSD Octal K8A 8-Pin tube-valve-basevery rugged, stable tube, close to Xf2 and Ruby® EL34this tube can be good used for Class-A and up to Ua=800VoltsRSD ® is a registered Trademark by BTB
Currently sold out
Octal K8A 8-Pin tube-valve-baseThe Carbon series pushs out the Maximum in details, 3D Room, low THDIt is the dot on the "i", mostly better than G.E.C. or TFK, check it outIt is extra handselected by BTB for best parameters, Audio and THDS4A ® "Selected For Audio" is a registered Trademark by BTB
Delivery time: ca. 1 - 5 days
Octal K8A 8-Pin tube-valve-baseThe Carbon series pushs out the Maximum in details, 3D Room, low THDIt is the dot on the "i", mostly better than G.E.C. or TFK, check it outIt is extra handselected by BTB for best parameters, Audio and THDS4A ® "Selected For Audio" is a registered Trademark by BTB
Delivery time: ca. 1 - 5 days
The EL34 Art series Mark 3 (Mk-III) is a very good alternative toPSVANE EL34PH tube - it sounds more warm and tight and has more low-endplus dynamic compared to the "T2" and the Treasure "Z" tube.Octal K8A 8-Pin tube-valve-baseheight: mm-socket diameter: mm-bulb diameter: mm
Delivery time: ca. 1 - 3 days
Octal K8A 8-Pin tube-valve-baseThe Premium EL34 for your Guitar or Bass Amp all brandsIt is extra handselected by BTB for low leakage and Premium matchingThe original sound and Power of the Amp is the Focus for this tubeThe tube is designed and made in EuropeS4GB ® "Selected For Guitar & Basses" is a registered Trademark by BTBheight:101mm-socket diameter:32mm-bulb diameter:32mm (info can variy!)EL 34
Delivery time: ca. 1 - 5 days
Octal K8A 8-Pin tube-valve-baseThe Premium EL34 for your Guitar or Bass Amp all brandsIt is extra handselected by BTB for low leakage and Premium matchingThe original sound and Power of the Amp is the Focus for this tubeThe tube is designed and made in EuropeS4GB ® "Selected For Guitar & Basses" is a registered Trademark by BTBheight:101mm-socket diameter:32mm-bulb diameter:32mm (info can variy!)EL 34
Delivery time: ca. 1 - 5 days
EL 34 with Octal brown base K8A 8-Pin tube-valve-baseThe Highgrade EL34 style =C= for your Guitar or Bass Amp all brandsIt is extra rated for mobile use - the extra rugged VersionThis tube has a good Power output and is Highgrade ratedThe tube is handselected in GermanyS4GB ® "Selected For Guitar & Basses" is a registered Trademark by BTBheight:97mm-socket diameter:32mm-bulb diameter:31mm (info can variy!)EL 34 C EL34 C EL 34C
Delivery time: ca. 1 - 3 days
EL 34 with Octal brown base K8A 8-Pin tube-valve-baseThe Highgrade EL34 style =C= for your Guitar or Bass Amp all brandsIt is extra rated for mobile use - the extra rugged VersionThis tube has a good Power output and is Highgrade rated and matchedThe tube is handselected in GermanyS4GB ® "Selected For Guitar & Basses" is a registered Trademark by BTBheight:97mm-socket diameter:32mm-bulb diameter:31mm (info can variy!)EL 34 C EL34 C EL 34C
Delivery time: ca. 1 - 5 days
EL34B Tung Sol sextet BTB Premium Matchinge.g. Unison S6, Unison Research Reference models, Airtight ATM-3e.g. Marshall custom high power rock headsOctal base | 6.3V heater 1.5A | 25W max plate rating
Delivery time: ca. 1 - 5 days
EL34B Tung Sol matched pair BTB Premium Matchinge.g. Unison Research S6, S8, Simply Italye.g. Marshall Plexi 1959, JCM800 2204 classicsOctal base | 6.3V heater 1.5A | 25W max plate rating
Delivery time: ca. 1 - 5 days
JJ EL34 quad, power pentode, octal K8A base, 6.3V / 1.5A heaterBTB premium matched quad for equal idle current in push-pull stagesWarm, smooth, earthy tone for hi-fi PP amps and 100W guitar headsGm 11mA/V typ., Ua 800V max, g2 8W max, burn-in 50-100h, made in EU
Delivery time: ca. 1 - 5 days
JJ EL34 matched pair in BTB Premium Matching.e.g. Octave V40 SE, Audio Research VS55.e.g. Marshall JCM800 2204, 1987X 50W.Octal | 6.3V / 1.5A | 25W max dissipation
Delivery time: ca. 1 - 5 days
JJ E34L matched quad, rugged power pentodes, octal, 6.3V / 1.5APrecisely matched on calibrated Roetest V10 for high-reserve PP useExtra headroom for rock and clean, clear voicing, still warm, tightFor Marshall DSL100, TSL100, JVM410 and stereo push-pull hi-fi amps
Delivery time: ca. 1 - 5 days
JJ E34L matched pair, rugged power pentode, octal, 6.3V / 1.5APaired on calibrated Roetest V10 plate stability and tight bassMore clarity and headroom than EL34 while staying warm and tightEL34 plug-compatible, check bias, burn-in around 50 to 100 hours
Delivery time: ca. 1 - 5 days
EL34EH Electro Harmonix matched quad BTB Premium Matchinge.g. Musical Paradise MP501, Fezz Lybra, Leak Stereo 20e.g. Marshall DSL100, JVM410H, Plexi 1959 HeadOctal base | 1.5A 6.3V heater | 25W max dissipation
Delivery time: ca. 1 - 5 days
Electro-Harmonix EL34EH power pentode, octal, 6.3 V/1.5 A heaterTwo output valves matched in-house by BTB at a practical 450 V pointFor compatible hi-fi and guitar push-pull stages using EL34 valvesRated 25 W plate and 8 W screen dissipation for each output valve
Delivery time: ca. 1 - 5 days
EL34 Psvane matched quad BTB Premium Matchinge.g. Unison Triode 25, YaQin MS-34B, Dynavox VR70Ee.g. Oldchen EL34, MP-501, McIntosh MC240 StereoOctal base | 1.5A 6.3V heater | 25W max dissipation
Delivery time: ca. 1 - 5 days
Octal K8A 8-Pin tube-valve-baseReplica Mix of Philips and Telefunkenheight:100mm-socket diameter:35mm-bulb diameter:38mm (info can variy!)EL34-PH MK2 PSVANE Pentode - Pentode Set of 4 pcs factory matched tubes
Delivery time: ca. 1 - 5 days
Genalex Gold Lion KT77 beam tetrode, octal, 6.3 V, 25 W plateFour output valves matched by BTB as one quad at a 450 V test pointFor compatible KT77 and professionally verified EL34 amplifiersCheck pin 1 wiring, bias, screen loading and heater capacity first
Delivery time: ca. 1 - 5 days
100% equivalent to EL34 applications, very reliable, very musical,clear, controlled low ends and good for distored Guitar Amp soundsheight:96mm-socket diameter:32mm-bulb diameter:32mm
Delivery time: ca. 1 - 5 days
The KT88 Art series Mark 3 (Mk-III) is a very good alternative toPSVANE KT88T2 tube - it sounds more warm and tight and has more low-endplus dynamic compared to the "T2" and the Treasure "Z" tube.Octal K8A 8-Pin tube-valve-baseheight: mm-socket diameter: mm-bulb diameter: mm
Delivery time: ca. 1 - 5 days
Octal K8A 8-Pin tube-valve-baseby RFT, Valvo specified, Valvo stamped, Valvo boxedEL 34 Valvo Pentode
Delivery time: ca. 1 - 3 days
EL34EH Electro Harmonix sextet BTB Premium Matchinge.g. Air Tight ATM-2, Jadis DA88, Unison Researche.g. Hiwatt DR201, Peavey VB-2 200W Bass HeadOctal base | 6.3V heater 1.5A | 25W max plate rating
Delivery time: ca. 1 - 5 days
EL34EH Electro Harmonix octet BTB Premium Matchinge.g. Audio Research Ref, McIntosh MC2102, Air Tighte.g. Marshall EL34 100 100, Mesa Strategy 400Octal base | 1.5A 6.3V heater | 25W max plate rating
Delivery time: ca. 1 - 5 days
EL34, 6CA7 & KT77 Output Tubes – Selection, Replacement and Hand-Selected Sets
What are output tubes and what are they used for?
Output tubes (power tubes) are vacuum tubes used in the power stage of an amplifier, where they amplify the audio signal to the required output power. They have a decisive influence on tone, volume, dynamics and, in guitar amplifiers, headroom as well as the distortion characteristics of the power stage.
EL34, 6CA7 and KT77 tubes are mainly used in guitar amplifiers and in many push-pull hi-fi power amplifiers. For technicians and service workshops, they are considered typical wear parts, as thermal stress and aging affect both sound quality and operational reliability.
What are the differences between EL34, 6CA7 and KT77?
EL34, 6CA7 and KT77 belong to a compatible tube family designed for similar output stage circuits, but they differ in construction and electrical characteristics. These differences influence bass control, midrange response, dynamics and headroom at high output levels.
The EL34 is regarded as a classic in European tube amplifier design, known for its pronounced midrange and early compression. The 6CA7 is often described as having tighter bass and higher robustness, while the KT77 typically offers greater linearity and dynamics. In hi-fi applications, the operating mode such as Class A or Class AB, as well as sonic performance at very low signal levels, also play an important role.
How do I choose the right output tube?
The selection depends on the circuit design, permissible power dissipation and the intended bias setting. It is essential that the amplifier explicitly supports the use of EL34, 6CA7 or KT77 tubes.
In many EL34-based designs, 6CA7 or KT77 tubes can be used as alternatives, provided that the bias current is correctly adjusted. Guitarists often focus on dynamics and playing feel, while hi-fi users prioritize neutrality and long-term stability. For B2B customers, reproducible measurement data and long-term availability are key factors. For meaningful advice, it is often helpful to send an inquiry email outlining specific requirements.
Why are hand-selected sets as pairs, quartets, sextets or octets useful?
Hand-selected tubes are measured according to their electrical characteristics and grouped into closely matched sets. This optimizes the sound quality of audio components and the tonal performance for guitarists.
Depending on the amplifier, pairs, quartets, sextets or octets are required to optimize stereo imaging in hi-fi systems and to minimize distortion (transformer symmetry). Especially in push-pull circuits and high-quality hi-fi or high-end power amplifiers, proper matching ensures the best sonic performance and reduced hum.
What should be considered when replacing tubes and regarding availability?
When replacing output tubes, correct bias adjustment is essential to avoid overload or sonic degradation. In addition, adjacent components such as tube sockets and coupling capacitors should be checked.
For end customers in Germany and Europe, having a reliable point of contact is particularly important, while professional users primarily focus on competitive pricing, short delivery routes and second-source options.