Londoner L100A solid state guitar amp - info and help required

[Wattsup]

I have recently acquired a Londoner L100A guitar amp which I am trying to find full details of online but I cant seem to find any official specs or manual for this amp and was hoping that someone here could possibly point me in the right direction or shed some light on these amps for me.

There also seems to be 2 versions that were produced that both share the L100a model number - the version with a black and white control panel and a version that has the silver and blue panel (which is the version that I have) and the differences seem to be more than just cosmetic.

The black and white panel amps have a semi parametric EQ on their Lead/Rhythm channel in the form of a 'Frequency' control and a 'Depth' control (along with the 'Bass, 'Treble' and 'Contour' controls for this channel. The silver and blue panel version however doesn't feature the 'Frequency' and 'Depth' controls and instead has a 4-way 'Tone Select' switch which is kind of unique and I would be most keen to know exactly what these 4 settings are adjusting in terms of frequency, gain, and bandwidth but I can't find any online manual or specs etc. Can anyone help me out here?

Other differences that I have noticed in photos of the 2 versions of the L100A amp is that whereas the Silver and Blue panel version provides a 'Bright' and 'Normal' input on its Bass/Organ channel (the same as its Lead/Rhythm channel), the black and white panel version offers a 'High' and "Low' input instead. The Black and white version also clearly states next to the volume control on the Lead/Rhythm channel that overdrive is achievable on settings of 4-5 but this isn't stated on the silver and blue panel version so I'm not sure if less gain is available on if this version has a different circuit board altogether?

If anyone is able to provide any info or history to these amps or point me in the direction of their specs, user manual or schematics, I would be most grateful.

[g1]

At least the B/W version is based on the Vermona Regent 100-G1.  That is the only one I found info for (from other threads on this forum).
Owners manual and schematic attached, you will have to check and see how far the schematic differs from the blue-silver version.

[Wattsup]

Thanks g1, much appreciated.
So was the Vermona Regent 100-G1 the very first version of this amp? If so, what was the history of the amp following this first release and how many variations were there?

[g1]

Sorry but I don't have any other info regarding these amps.  I didn't find anything online either.  The schematics came up in a repair related thread.

[Wattsup]

Sorry but I don't have any other info regarding these amps.  I didn't find anything online either.  The schematics came up in a repair related thread.

Yeah, not much available at all for these amps, a bit of a curiosity for sure.
I know that they are nothing high end or anything to get excited about but that 'Tone Select' on the version of the Londoner L100A that I own is quite unique and provides some interested and extreme tonal sculpting so I would love to know what those 4 settings are adjusting exactly in terms of frequency, gain, and bandwidth etc. Unfortunately the Vermona Regent 100-G1 version of the amnp doesn't feature that Tone Select so there is not explanation in the manual that you kindly provided.   

[dmeek]

Can you post photos of the circuit boards, both sides?

[Wattsup]

Can you post photos of the circuit boards, both sides?

Yeah, sure thing. I will get some photos taken and post them up in the next day or 2.
Can you insert images directly on to a post here or does it require an external hosting site?

[g1]

Can you insert images directly on to a post here or does it require an external hosting site?

Click on the "preview" button and you should be given the option for attachments.

[Tassieviking]

It sure looks like this one in the other repair thread
https://www.ssguitar.com/index.php?topic=5359.0

[J M Fahey]

Looking at Tassieviking´s schematic, I was impressed by finding a "modern" amp.

I half expected that an amp made by a State run East German Kombinat (Socialist style Factory) would be very boring old school but no, the design holds its own.

The pot adjustable "Parametric EQ" is actually a Wien Bridge based deep notch filter, where you can continuously select Frequency between 200 and 2000 Hz, a very useful range for Guitar, and a pot adjustable Depth, from flat to -20dB

The 4 position rotary switch version probably selects 4 from the many possible sounds.
Not bad at all.

You can mimic the EQ of various "famous" amps, say Fender Tweed/blackface/silverface or Marshall or VOX 
Very clever.

[dmeek]

The Londoner L100a in this thread has ICs.

https://www.ssguitar.com/index.php?topic=4315.0

The schematic in post #8 might be for the earlier non-A version.

[Wattsup]

The Londoner L100a in this thread has ICs.

https://www.ssguitar.com/index.php?topic=4315.0

The schematic in post #8 might be for the earlier non-A version.

Yeah, the Londoner L100A in that thread is the black and white panel version with the 'Frequency' and 'Depth' parametric controls. Here is a photo of mine, which as you can see has the 4-way 'Tone Select' control instead.

[Wattsup]

Can you post photos of the circuit boards, both sides?

As requested...

[dmeek]

Here is the preamp schematic. The Tone switch is a gyrator notch filter. I can't see the value of the silver capacitor on the tone board but if
I assume it is 1000PF the frequencies are: 1 - Flat, 2 - 230Hz, 3 - 1kHz, 4 - 3.4kHz. If you can read the value, let me know.
I couldn't draw the reverb section because the foil side is hidden by the footswitch jack. If you can move it and post a photo I can do it.
If you want to lift the power board and post a photo of the foil side I can do that too.

You cannot view this attachment.

[g1]

Just amazing work, dmeek, as usual.