Home FAQ
Frequently Asked Questions

 

Q. I Already Own an Epiphone Valve Jr. -or- Harley Benton GA5 -or- Blackheart -or- VOX AC4TV Amp, Can you Modify it for me?

A. Yes, Not a Problem. Take a Look at the Available Modifications, Decide what you want Done, then Email me with your Requirements. I will give you a Quote for the Work. 

 

Q. Is 'OPR' (Output Power Reduction) Really any Good?

A. I have tried all of the Alternatives, they all work to some degree but 'OPR' (Power Scaling) is The Business, It works Brilliantly and is Extremely Reliable. Almost all Valve Amps Sound Great when they are 'Cranked', but how often can you Crank your Amp without somebody complaining - 'It's Too LOUD!!' - With 'OPR' you can Crank your Amp every time you use it - Then just turn the 'OPR' Control Down to an Acceptable Volume - The Tone will stay the same. 'OPR' is the BEST and nothing else can touch it!

 

Q. What about Tone Controls?

A. I Mainly use two different types of Tone Controls depending on the Amp- A Single ‘Tone’ Control which Allows Selective Boost or Cut of the Upper or Lower Frequencies of the Input Signal. The 'Mid' Frequencies are Maintained. This 'Tone' Control does NOT Obstruct the Signal Path, Preserving the Amps Detail, Clarity and Volume -and- The Full ‘Tone Stack’ which includes ‘Treble’, ‘Middle’ and ‘Bass’ Adjustment. In most cases the Configuration used is a 'Hand Wired' Passive Tone Stack using 'Orange Drop' and 'Silver Mica' Tone Capacitors - The Tone Stack is Configured so that it can Completely Remove the 'Treble', 'Middle' or 'Bass' from the Signal (if required) and Replicates a 'Fender Twin Reverb' in Operation.

 

Q. What about Valve Rectifiers?

A. Yes, A Fantastic Sounding Modification to any Valve Amp. All Amplifiers use a Rectifier to convert the Raw AC Voltage from the Mains Transformer into DC Voltage. The Amp Circuits Need DC Voltage to work. If, for example, you Hit a Power Chord on your Guitar, the Amplifier Circuitry Suddenly Demands a Large Dose of Power from the Mains Transformer. Silicon Diodes are Extremely Efficient and can convert the Raw AC into DC almost instantaneously - to Feed the Amplifiers Needs. Valve Rectifiers are a Different Story. Generally Speaking, they can't Cope with Sudden High Demands of Energy and they 'Starve' the Amp of Power until they can catch up with the Demand - This is Called 'SAG' - and it Sounds GREAT!  The typical sound Produced by an Amp using Silicon Diodes would be -

Attack-Sustain-Release-Decay. 

Using a Valve Rectifier, the sound would be Closer to -

Attack-Swell-Extended Sustain-Release-Decay. 

In Most Cases, A ‘Tri-Rectifier’ Switch can be added to the Amp so that you can select between ‘Silicon’ or V1/V2 ‘Valve’ Rectifier. For Me, You Can’t beat the 'Feel' of a Valve Rectifier.

 

Q. What about Speakers?

A. For my Smaller Combo Amps I always use a Celestion ‘Super 8’. It’s a Fantastic sounding Speaker well suited to a Small Valve Combo. There is nothing to stop you using any Speaker Combination you like. Even the 5 Watt Amps will drive a '4x12' Cab. Larger Speakers do Sound better and are a Lot Louder.

 

Q. What about the Output Transformer?

A. The Output Transformer is perhaps the Most important part of any Valve Amplifier. It converts the High Impedance, High Voltage 'Valve' Output - to -  the Low Impedance, Low Voltage 'Speaker' Output. The Better the Output Transformer, the Better the Sound, without Question. In the Case of the Epiphone Valve Junior or Harley Benton Amps, the Best transformer for the Job is a 'Hammond 125DSE'. These are Excellent Transformers and will Nearly Double the RMS Output of the Amp. A Superb Modification and well worth the extra cost.

 

Q. What about the Valves?

A. I have a ‘High-Gain’ Test Station in which all Valves that I use are tested. Any Valves that are Mechanically ‘Noisy’ or ‘Microphonic’ are Rejected and Replaced with Known Good Valves. Today's Standard of Valve Manufacturing is Poor and it is quite a Task to acquire ‘Quiet’ Valves. For me, it is more important that the Valve is working Correctly and is ‘Quiet’ than any other Factor.  In the Past, I have Rejected up to 30 Valves in order to find just 1 that works to my satisfaction.

 

Q. I know about ‘OPR’ but what is ‘OPR-1’ and ‘OPR-2’?

A. 'OPR-1'....This is the Standard Method of 'OPR' in which Only the HT Voltage of  the Output Valve/s is Reduced, the Preamp Circuits are 'Held' at Normal HT Supply Voltage. This Maintains the Full Preamp Drive and High Harmonic Content of the Valve Output Sound.  'OPR-2'.... This Setting Totally Changes the Dynamics of the Amplifier as the HT Voltage of  Both the Preamp and Power Amp Circuits are Reduced. The Resulting Effect is a 'Cleaner', 'Softer' Sound.  

Q. What about 'Dual Output Valves'?

A. The Final Sound of any Valve Amplifier is Determined by many Factors but one of the Major Players in the Circuit is the Type of Output Valve Fitted. An 'EL84' sounds totally different to a '6L6GC'. Some of the 'RAT' Amps are fitted with 2 Different Output Valves and you can 'Switch Between' them -or- 'MIX' them -or- Have them Both Running all of the Time (Dual Parallel). It all adds up to a Much more Versatile Amp and Something a Bit different to the Standard, Run-of-the-Mill - 'Valve Amp'.