An ideal replacement for standard EL34 and 12AX7 (ECC83) valves in Marshall guitar amplifiers or other high power audio amps, or for use in DIY build Hi-Fi amplifiers.
EL34 pair factory matched to within 1mA anode current.
Sent by First Class post for fast delivery.
This is an ideal upgrade replacement set of valves for Marshall models: DSL50 Double Super Lead, TSL60, TSL601, TSL602, JCM600, JCM601, JCM602, JTM 50 and JTM60 Series - 1961 Lead, 1962 Bass, 1962 Lead, 1963 PA, 1985 PA, 1986 Bass, 1987/1987T Lead, 1989 Organ and any other guitar amp using two EL34s and four 12AX7s.
Useful Bias information below, with acknowledgements and thanks to Marshall; Please remember that these amps run at around 500 Volts and be very careful not to touch any exposed live circuitry, and use a tool with an insulated handle whilst setting the bias!! MARSHALL SERVICE BULLETIN SUBJECT: Bias Info/Procedure for JCM2000 series Marshall amplifiers THEORY OF OPERATION: We are setting the bias using the current method instead of cross over distortion method. The Bias PCB assembly is as follows: PR1: Bias mini-pot adjustment for pin1 which is one side of the push pull amp (two output tubes in a 100watt amp and one output tube in a 50watt amp). Pin1: Connected to the cathode of the output tube(s) which then goes through a 1 ohm resistor then to ground. Pin2: ground reference. Pin3: Same as pin1 but for the other side of the push/pull amp. PR2: Bias mini-pot adjustment for pin3, the other side of the push/pull amp. PROCEDURE: 1. Make sure amplifier is connected to a load with the proper impedance selected. 2. Power up amplifier on STANDBY and let the circuit stabilize for a couple of minutes. 3. Locate the male three pin molex connector (CON2) with the two mini-pots (PR1 and PR2) on both ends found on the bottom of the tube bay. 4. Connect DMM (set to read mV) with alligator leads, reference common lead to center pin (pin2) on molex connector CON2 and positive lead to pin1 on CON2. 5. Take amplifier off of STANDBY with no signal, adjust mini-pot (PR1) closest to pin that the positive lead from your DMM is connected to and set it to the mV voltage that is listed in the chart below. 6. Repeat steps 4 & 5 for pin3 and until both pin1 and pin3 mV are the same. BIAS CHART mV SETTINGS (pin1 and pin3) DSL50 45mV TSL60/1/2 80mV DSL100 90mV DSL401 1.375V TSL100/122 90mV DSL201 .675V
Shuguang EL34 testimonials from around the Web, with acknowledgment and thanks...
“The sound is very clear with good dynamic range. Top end has nice extension but never bright, with great texture in the mids and bass.”
“I find the Shuguang EL34-B to be a very warm sounding tube with a magic midrange. Highs are excellent, but not to sharp. The bass is there but also very well controlled. After about 100 hours they really come alive. They are much louder and CLEARER then the other tubes I've tried. That's the true magic of this tube, the clarity, they really help my Triangle Celius 202 speakers image very well. They also produce a very accurate and uncolored sound. For the money, I can't imagine they can be beat.”
''The sound is loud and clear with a very nice sonic range. Not excessive in tops, mids, or bass, they are accurately described as well balanced. The sample tested had no audible microphonics and an average background noise level. Harmonic content was rich, lending that pleasant ''swirl'' and sustain that guitar players crave''
“.... if I had to pick one for best tone it’d be the Shuguang EL34-B….Once I can convince a customer to try the EL34-B, they almost always come back for more. The Shuguang folks make excellent glass….”
Should you be in any way unhappy with your purchase within 28 days of purchase, you may return the item for a full refund of the purchase price. |