Main features
The two channels (A and B) share the equalization section, but each of them provides an indipendent pre control, a reverb and the Master Volume.
Front Panel
A
At lower settings of the pre, it produces a very clean sound. Turning up the level will add a slight overdrive, so to create a good crunch tone.
Pre
Turning up it will create a medium drive, always growing. A crunch perfect for rhythm.
B
It boosts Gain, so to go from a classic distortion to modern distortions.
The equalization
4-band. It is shared between the two channels. Circuit is passive. It provides 4 controls for Treble, Middle, Bass and Presence.
Standby
It is useful to prolong tubes life. Use this switch during brakes, and not the Power.
Rear Panel
Effects Loop
Use this switch to match the level to your effects processor. The two possible values are -10dBV and +4dBm. Generally, higher settings are suitable for racks, while lower settings for pedals.
Send & Return
These two jacks provide the connections for the processor.
Recording Compensated Line-Out
The JCM 900 4101 signal, filtered, can be sent to a recorder or a Mixer.
Direct Line
If you want to use only the pre signal.
Loudspeakers
You can connect two cabinets.
Impedance
This switch is useful to match the output impedance to the additional speakers.
|
Price |
700 Euros |
|
Type |
Combo |
|
Output (RMS) |
100 Watts |
|
Speaker |
12" Celestion G12-100 (1) |
|
Ohms |
8 Ohms |
|
Pre tubes |
3 x ECC83 (12AX7) |
|
Power Amp Tubes |
4 x 5881 |
|
Channels |
Two (A and B). A has been planned for clean tones and Crunch rhythm. B provides a great amount of gain for lead tones. Each is equipped with indipendent controls for Volume, Pre and Reverb. |
|
Standby |
Yes. It must be used during breaks so to preserve tubes life. |
|
Effects |
The 4101 provides a separate reverb for each channel, with a level control. |
|
Equalization |
4-band EQ |
|
General Controls |
Presence, bass, middle, treble |
|
Series Effects Loop |
Yes |
|
Special features |
Recording Compensated Line-Out and Direct Line. The first Line-Out provides a filtered sound for recording, while the Direct Line provides an unfiltered pre signal for connection to an additional amplifier. |
|
Level |
Yes (-10dBV/+4dBm) |
|
Additional Speakers |
2 |
|
Footswitch |
Optional. P802 Dual (2 buttons for channel and reverb) |
|
Dimensions (mm) |
500 x 470 x 290 |
|
Weight (kg) |
23.9 (54 lbs) |
Conclusions
100 Watts are an enormity and give you the possibility to play everywhere. If you want to use it at home with some cabinets, buy the PB100 Power attenuator or you will never obtain the distortion you expect from a JCM 900. The JCM 900 4101 was introduced in 1990 and discontinued in 1999, so you can find it only used at a price, approximately, of 700 Euros.