The only way to switch channels is to move your cable to the channel input for the channel that you want to use.

Yes, in addition to the cabinet that comes with the amp, you can hook up an 8Ω cabinet. Both the stock 15" cabinet and your additional one need to each be plugged into one the two 4Ω inputs.

We made sure that the circuits inside this amp were as close to the originals as humanly possible all the way down to the hand wired turret boards using the absolute highest quality components available. So yes, they will give you that sought after, hard to find "round sound" that the B-15 is famous for.

One of the signature sounds of the B-15 is the warm overdrive that is easily achieved. Partially due to the low power output section of this amplifier, it doesn’t quite have the clean headroom of modern amplifiers. This amp is all about tone rather than volume.

The Heritage B-15 was specifically designed to be used with the stock tube types and should not be substituted.

The HR-12R is equipped with a Premium 8 ohm 12” Celestin Alnico Gold speaker

Yes. You can hook up an additional 8 ohm speaker to the External Speaker jack that is located on the back of your amp.

Tube availability has changed quite a bit since 1961 when the original Reverberocket was at the height of popularity. The original 6V6 power tubes used back then simply aren’t as easy to get anymore, so we varied the circuit slightly to accommodate the 6L6. Same goes for the 5Y3 rectifier tube that we’ve replaced with a 5AR4.

When connected, the included 2-button footswitch will turn on and off the amp’s reverb and tremolo.

Your amp is equipped with 2x 6SL7 & 2x 6SN7 in the preamp, 1x 5AR4 for the rectifier, and 2x 6L6GC power tubes. Tube replacement may become necessary after one to three years, depending on environment, usage and care. Generally speaking, a tube does not need to be replaced unless it becomes noisy or microphonic.

The PF Series amps are capable of driving cabinets up to a total impedance of 4 ohms. This means either one cabinet rated at 4 ohms or two cabinets rated at 8 ohms each.

When you have two 8 ohm cabinets connected, the output (watts) is essentially split between the two cabinets.

Class D amplification is a relatively new type of amplifier design. The sophisticated circuitry makes it possible to pack more power than ever into smaller packages while dramatically lowering the weight. Part of what makes the increased power a possibility is the incredible efficiency that Class D is capable of. Class D is around 75% efficient while traditional Class A/B is around 20%.

Whatever you put in the Audio In jack will only come out of the Phones jack. This is for jamming along with your favorite record late at night when you can’t play loud for example.

The red LED that is located near the input jack is a very important indicator to watch. What it is telling you when it is flashing can be a few different things. Your bass output is too high, the Gain control is too high, you have your EQ (bass, mid, treble, boost switches) turned up too high, or any combination of the three. To solve the problem, turn your master volume all the way down, EQ set to noon, boost switches out. Now play your bass normally and adjust the gain control so that you can play how you prefer without lighting up the Peak LED. Now you can go ahead and turn up your master volume to a normal level and adjust your EQ to your taste. At this point if you see your peak LED lighting, you may want to turn down your master volume or bass EQ a bit. On the PF-350 you can engage the Limit switch which will help calm down the hot signal being sent to the power amp.

While they both provide the same function which is to deliver the amplifiers output to your cabinet, there are certain benefits of using a Speakon connector over 1/4”. They lock into their sockets preventing accidental disconnection, shield any contacts from human touch, and do not short out when being connected or disconnected while the amp is powered on.

What you are connecting your XLR line out to will determine what to do with this switch. If you are going from this output directly to a mixers Mic input, then you want to have this switch pushed in. If you are plugging it into something like an external power amp or powered speaker you would have this switch out.

There are a bunch of things to consider here. If you're having trouble with your amp cutting out because you keep having to turn up, it's possible that you need a beefier amp for the gigs you're playing.
One of the first things to try is to use a 4 ohm cabinet ( or TWO 8-ohm cabs) instead of a single 8 ohm. At 8 ohms, the PF-350 or PF-500 will put out 250 watts- at 4 ohms, 350 watts. That alone will help give you some more headroom. We don't make a 4 ohm 2x10 cab, but the SVT-212AV is a great choice for 4 ohms.

We do have some 2x10 cabs if that's what you really like (PF-210HE or PN-210HLF are both nice), but my concern is that if you're struggling now, you'll still be struggling unless you pair one of those with a second 8-ohm cabinet or a higher-powered amplifier.

Having the 2 inputs is more a convenience than a necessity. Some amps have two inputs, one for active the other for passive. Others have a single input with a Gain knob, and some have a padded selector switch. Some even have a combination: input jack with active/passive switch and Gain knob.
These are all different ways of accomplishing the same thing: preventing a high-output active bass from pushing the amp into unwanted distortion/clipping. When set to Active, the signal is reduced, aka "attenuated", or "padded". A nice feature is a clip light that tells you when the amp is clipping. (Note: for some of us, clipping can be a good thing, especially with tube amps or preamps).
Use the -15db pad if you notice that the peak/mute LED comes on regularly.

At the end of the day, use your ears and pick the one that sounds the best to you.

No, this is not recommended, as this amp is rated for a minimum of 4 ohms. Running at 2 ohms could overwork your head and lead to premature failure.

The PF-350, PF-500, and PF-800 have a voltage selector on the back near the IEC input. Make sure the switch is in the correct position for your local AC mains voltage before you plug in the AC power cord.

We don't make specific rack ears for those products, but we've seen some people take a generic rack shelf and mount their PF amplifier that way.

The PF-350, PF-500, and PF-800 have a warranty of 2 years for electronics, effective from the date of purchase. The warranty is non-transferrable. The original receipt / proof of purchase qualifies as the official warranty card.

Yes, plugging in to the 'power amp in' jack completely bypasses the preamp circuit.

You will only need one cable between your head and the cabinet. The second jack is for daisy-chaining in parallel to a second cabinet.

The PN-115HLF, PN-210HLF, and PN-410HLF has a warranty of 5 years for electronics and 2 years for speakers, effective from the date of purchase. The warranty is non-transferrable. The original receipt / proof of purchase qualifies as the official warranty card.

The GAIN knob varies the amount of signal driving the preamplifier. The MASTER knob controls the overall output level.

This switch, when depressed, sends a post-EQ signal to the Bal. Out jack. When this switch in the out position, the signal at the Bal. Out jack is pre-EQ.

The preamp out is post EQ

Yes. The two identical outputs are wired in parallel, and you can use either one, or use both. Make sure the total speaker impedance load is 4 ohms or greater. For example, you could connect: Two 16 ohm speakers (an 8 ohm load), Two 8 ohm speakers (a 4 ohm load) or one 4 ohm speaker. NOTE: When connecting multiple speaker cabinets to the amplifier, keep the overall impedance at or above 4 ohms.

This unit has two quarter inch outputs and a speakon output.

No you cannot run the SVT-VR without a load/speaker cab because it will damage the tubes and transformers.

The standby mode allows the tubes to warm up or remain warm without high voltage being applied to them. This helps to extend the life of the tubes. The standby switch should be off when first turning on the amp. Let the amp warm up for at least 20 seconds before turning on the standby switch. During short periods of non-use, the amp should be put into standby mode. For long periods of time of no use you will want to turn off your amp.

Preamp Tubes: (4) 12AX7 (4) 12AU7 / Power Tubes: (6) 6550

The lives of the tubes in the SVT-VR depend on how often and how hard you use the amp. Power tubes should be checked at least once a year – more frequently if you use the amp every day. When the power tubes begin to wear out you will start to notice a lack of punch, noise and lack of volume.

The preamp tubes aren’t worked as hard as the power tubes and typically last longer. If a preamp tube starts to go bad, the amp may squeal, get noisy, lose gain or have no input signal.

The Standby/Power LED will flash between red and green when the amp sees a problem with the power tube circuit on the SVT- VR and will turn off the output. This usually means that you have a bad power tube.

Yes. Just make sure your impedance switch on the back of the amp is in the 2 ohm position.

Running the SVT-VR at 8 ohms is not recommended. The Output transformer is tapped for 2 and 4 ohms; running anything other than 'nominal' impedance can put excessive strain on the OT and the tubes, leading to a premature failure.

You would need to use an external step-up or step- down transformer that converts your country's voltage to 120V AC.

Yes, plugging in to the 'power amp in' jack completely bypasses the preamp circuit.

The SVT-VR has a warranty of 5 years for electronics and 90 days for tubes, effective from the date of purchase. The warranty is non-transferrable. The original receipt / proof of purchase qualifies as the official warranty card.

No you cannot run the SVT-2PRO without a load/speaker cab because it will damage the tubes and transformers.

No the SVT-2PRO can only run at a 2 or 4 ohms load. Having an 8-ohm load on the SVT-2PRO will damage the amp.

The life of the tubes in the SVT-2PRO depends on how often and how hard you use the amp. Power tubes should be checked at least once a year – more frequently if you use the amp every day. When the power tubes begin to wear out you will start to notice a lack of punch, noise and lack of volume. The preamp tubes aren’t worked as hard as the power tubes and typically last longer. If a preamp tube starts to go bad, the amp may squeal, get noisy, lose gain or have no input signal. One exception is the phase inverter tube, it is a good idea to change this one when replacing your power tubes.

The SVT-2PRO uses 4 rack spaces.