This Amp is now an Icon - It has to be one of the most Modified Valve Amps of all time. The Amp is a Great ‘Base’ to work from, it’s Simple design leaves it wide open to just about any Modification. With just a Few component changes, the Standard 'DULL' Amp can be Transformed into a real Performer. The Internet is Cluttered with sites devoted to Modding the VJ, some offering good information and others not worth looking at. Contrary to Popular Belief, these Amps are NOT 5 Watts. The True RMS Output is no more than 3.6 Watts with the PEAK Power Output being about 6 Watts. This is Mainly due to the Small Output Transformer.

The Modifications that I do are More Sophisticated and Go Beyond the Scope of the average Modder. I have spent Countless Hours sat in front of an Oscilloscope, Tweaking and Fine Tuning the Designs. The ‘Hot-Rod-Valve-Special’ (HRVS) Amplifiers that I Produce Represent Exceptional Value for Money and are Difficult to beat in Performance, Features and Price. The Addition of ‘Power Scaling’ and ‘PS1+PS2’ to these Amps puts them in a 'Class of their Own' and allows the Amp to be used in any environment, From your Bedroom to the Stage.

History

Epiphone Valve Junior V1 - The First of the Breed. Excessive Heater BUZZ due to Very Poor PCB Design. Not a Nice Amp and Rapidly Replaced with the V2.

Epiphone Valve Junior V2 - Second Issue with a redesigned PCB, DC Valve Heaters and Additional Power Supply Smoothing. A LOT Better than the V1 but still with some ‘Noise’ Issues and other Serious Faults present, from the V1 design. No Longer Made.

Grainger Valve Edition 5 - Exact same Amp as the Epiphone VJ V2. Made in the Same Factory, just a Different Name Badge on the Front of the Amp - No longer Made.

Harley Benton GA5 - The Same Amp as the Epiphone VJ V2 with the addition of an ‘EQ’ Control and Re-designed ‘Cream’ Colour Cabinet - Made in the Same Factory, just a Different Name Badge on the Front of the Amp - In Current Production.

Epiphone Valve Junior V3 - Third Issue with Up-graded Output Transformer, Several Component Changes on the ‘Black’ PCB and a Nice ‘Eminence’ 8 inch Speaker. A Vast improvement over the V2 Design but it Still has some ‘Issues’. In Current Production.

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This is a List of the More Complicated (Deluxe and Standard) Modifications that I do to the ‘VJ’ Style Combo and Head Amplifiers. The ‘HRVS’ Amplifiers that I produce will include some or All of these Modifications, depending on the Final Price.

All of my 'VJ' Style Amps have the Standard Bias and Voltage Modifications done, These are the Mods that you will read about on the Internet Forums. Not worth Detailing - Everybody knows about them.

Deluxe Modifications - Special Order Only

1. Dual Master Volume Controls - The Master Volume Control sets the Final Valve Output. This Mod Includes 2 x Master Volume Controls- Master '1' and Master '2'. You can set these Controls at different Volumes and then Switch Between them using a Foot-switch. This is about as close as you can get to a 2 Channel Valve Junior. Switching is Analogue and there are NO Thumps or Clicks when the Foot-switch is used.

2. Treble, Middle and Bass Tone Controls - A Full Tone Stack can be fitted to the Valve Junior. Not really Necessary in my Opinion, but if you want it, I can do it.

3. Point-2-Point Hand Wired Chassis - The PCB is Removed from the Amplifier and ALL connections between Components and the Valves are Point-2-Point Hand Wired via 'Tag Strips'. This is Extremely Time Consuming to do, but Definitely makes the Amp Sound Better.

4. 15 Watt Push-Pull Conversion - The Amp is Changed from 'Single Ended' -to- 'Push-Pull' Configuration. Using a '12AT7' -or- '12AU7' Valve as the Phase Inverter and 2 x 'EL84' Valves as the Output Stage into a 30 Watt 'OEM' Output Transformer. This Makes the Amp a LOT Louder with Much more Gain Available. It still 'Looks' like a VJ but with a Real 'BITE'. To make the Most of this Modification the Amplifier needs to Drive at least one 12" Speaker.

Standard Modifications

1. Power Scaling - This is the Business and essential for an Amplifier used in the Home. I Have tried ALL of the other systems that claim to Reduce the Volume without changing the Tone - This is the ONLY one that really works. 'RAT Electronics' is Licensed by 'London Power’ to Install this Technology and Pays a License Fee for each Installation.

2. PS1+PS2 - - 'PS1'....This is the Standard Method of 'Power Scaling' in which only the Valve Output Circuits are Scaled. The Preamp Circuits are 'Held' at Normal Supply Voltage - - 'PS2'.... This Setting Totally Changes the Dynamics of the Amplifier as Both the Preamp and Power Amp Circuits are Scaled. The Resulting Effect is Known as 'Brown Out'. The most Well known user of 'Brown Out' was 'EVH'. He used a 'Variac' to Achieve the 'Brown Sound' but the End Result is the Same as 'PS2', without the Risk of any Damage to the Valves. Most 'RAT' Amps are Fitted with ‘PS1’ and ‘PS2’ as Standard.

3. Dual Output Valves - The Amplifier is Fitted with 2 x Different Output Valves, usually an ‘EL84’ and ‘6L6GC’. You can Switch between the Valves for a Totally different Amp Sound.

3a. Dual Output Valve 'MIX' Function - This System is based around one Rotary Control. The Amplifier is Fitted with 2 x Different Output Valves. The Rotary Control Allows Selection of Just One Valve or the Other (EL84 -or- 6L6GC) -or- Any 'MIX' Between the Two Valves. Using the 'MIX' Control you can get a Great Bit of 'Brit Crunch' (From the EL84) Mixed in with the 'American Clean' (From the 6L6).

4. Twin Rectifiers - This Modification uses a 'GZ34/5AR4' Valve Rectifier and requires the Standard Mains Transformer to be Changed. You can then Switch Between the Stock ‘Silicon Diodes’ and the 'GZ34 Valve’. The ‘SAG’ Sound produced by a Valve Rectifier is the Best.

4a.'TRI' Rectifiers - This Option uses an 'EZ81' Valve Rectifier which Integrates Seamlessly into the VJ Circuit and offers 3 different types of Rectification along with a Variable 'SAG' Control. It uses the Standard Mains Transformer.

5. New Output Transformer (OPT) - Changing the OPT to a Decent Quality Unit will Double the Output of the Amplifier from 2.6 Watts to 5 Watts RMS. That is not the Only Benefit, it will offer Better and Tighter ‘Bass’ Response along with Cleaner and Clearer ‘Mids’ and a Much better Defined ‘Top’ end. These Transformers are Expensive but well worth it.

6. Dual Output Transformers - The Amplifier can be Fitted with 2 x Different Output Transformers and a Switch to select the one you wish to use. This makes the Amp Loads more Versatile.

7. Master Volume Control - If the Preamp Valve 'Bias' is Correct, a Master Volume Control will allow - Preamp Overdrive Only -or- Power Amp Overdrive Only -or- Both. All 'RAT' Amps have a Master Volume Control.

8. Three Position Valve ‘Bias’ Switch - Switches the Preamp ‘Bias’ between - ‘Negative Feedback’ -or- ‘Sharp+Clean’ -or- ‘Medium/High Gain’. Exclusive to 'RAT' and fitted on All Amps.

9. Three Position Valve ‘Gain’ Switch - ‘Center’ Position is VJ Factory Standard - ‘UP’ is Medium 50% Gain - ‘Down’ is High 100% Gain. This Switch works well in conjunction with the ‘Bias’ Switch and gives the Amp some real BITE. Fitted on all 'RAT' Amps.

10. Tone Control - 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. Fitted on all 'RAT' Amps.

11. Line Out and Headphone Sockets - Nothing Special here but these Sockets are Fitted on almost all 'RAT' Amps.

12. Two x Speaker Outputs and Impedance Select - The Output Transformer usually offers individual Speaker Outputs of 4, 8 and 16 Ohms and this Must be Correctly Matched to the Speaker/s in use. The 'RAT' Setup is Simple and Straightforward to use - Connect a Speaker or Speakers and select the Correct Impedance - Done. Fitted to all 'RAT' Amps.

13. I usually Fit a Celestion 'Super 8' Speaker to the V1 and V2 Amps. It is the Best Speaker for the Job and has a Great 'Rock' sound when Pushed. It is an 8" Speaker Rated at 15 Watts, 8 Ohms. The V3 Amps are Fitted with a Very Nice Sounding 8" 'Eminence' Speaker. I leave that Speaker in Place.

14. There are Several 'Other' Modifications that I do to All of my Amps that are Exclusive to me and both Enhance Performance and Help to Keep the Noise Levels Way Down.

The Background 'Hiss' from the ‘HRVS’ Amp is so Low, you may not notice it is Switched on.

Short 'Power Scaling' Sound Clip