Bogner Alchemist mods

  • Thread starter Thread starter DredNowt
  • Start date Start date
D

DredNowt

New member
Hi all first post!
Recently got an alchemist in trade and it's my first bogner. I love it but it didn't come with a footswitch and I can't find any for sale so I'm having one made? Which got me thinking of customisation.

has anyone had their mitts in the amp's guts? Are there more switching possibilities? Can I switch the gold channel between clean and crunch?
Any way to alter the boost? As it seems more of a fattener than 'time to melt faces with a solo' button.

thanks in advance.
 
This is an amp that's been on my list for a while to check out, but they don't seem all that popular so mods are few and far between.

So I'm speaking speculatively instead of from direct experience here - but there is a highly detailed Alchemist service manual available online with a lot more information than we usually get for amps. It looks like the boost for Ch2 is just a simple switch that adds R38 and C26 to the signal path - which I think is just changing the brightness allowed through between tube gain stages 2 and 3. So it's not adding a "boost" in the sense of adding a boost in front of the amp would be, it's probably lowering the bright values to allow more low freqencies to pass through to the next gain stage. You could easily tweak those values but it's never going to add a bunch of gain as in, shredding solo kind of gain.

You could add a switch to go between clean and crunch but there's probably a volume difference between those two modes that would mean you'd either have to add a separate volume control or do some other trickery to make it usable. There are also multiple relays attached to that crunch switch - it's not just one signal path being changed, it's multiple spots. RLY1 does something with the V1B tube bias, cold clipper it looks like? Someone can correct me there if I'm wrong. RLY2 looks like it mixes in another gain stage V2A. You may need to add another relay and drill a hole for another volume pot to match the volumes across different volume levels, it usually isn't as easy as adding a fixed signal bleedoff to match the volumes because matching volumes will be different at lower DB's than higher DB's, if that makes sense.

You could use the boost switch to add my gain by perhaps adding some diodes or some similar pattern in there, but it might get complicated. The Marshall Mk III amps had a diode clipping stage between 2 & 3 and I think those sound awesome so maybe you could do something like that, using that switch to add some fixed clipping to the signal there - but it's not going to sound like a boost before stage 1, just to be clear.

Here's the link to the service manual by the way. And to give credit where it's due, I originally found it on EL34World: https://totallyradguitars.com/s/Line_6_alchemist_sm.pdf

Cheers and good luck! Eventually I'll get my hands on one of these and maybe I'll have more ideas then.
 
Last edited:
I owned one very briefly, didn't sound like a Bogner to me.
 
Geo said:
I owned one very briefly, didn't sound like a Bogner to me.
Click to expand...
Yeah i've heard that a few times, it's based on a Fenderish sound rather than a Marshall. Still better than 80% of the other amps i've used.
 
DredNowt said:
Yeah i've heard that a few times, it's based on a Fenderish sound rather than a Marshall. Still better than 80% of the other amps i've used.
Click to expand...
It's a decent quality amp, I just couldn't get it to sound like I wanted to.

I tried speakers, tubes, everything I could think of and then passed it along.
 
Last edited:
I think they sound alright, but if the "Bogner" sound in your head is Uberschall or Ecstasy Red, yeah it's not like that. But you could say the same about a Goldfinger, I have an old GF45 and it sounds great, but if I took the logo off the front no one would hear it and say "oh yeah that's a Bogner."
 
Geo said:
I owned one very briefly, didn't sound like a Bogner to me.
Click to expand...
Because it's really a Line6 with design input and licensing from Bogner. Its got a parallel loop and the delay and verb are line6 digital FX
 
  • Like
Reactions: Geo
scottosan said:
Because it's really a Line6 with design input and licensing from Bogner. Its got a parallel loop and the delay and verb are line6 digital FX
Click to expand...
That's exactly what it sounded like, but it seemed well built.
 
I've owned, fixed and modded a couple of these.

It's not a Marshall based amp, nor has it ever been advertised like one. Those expecting a cheap MIC XTC, look somewhere else. That said, it's not a bad amp at all, if you take it for what it is: Clean channel has a Dumble tone stack, clean boost is a mid boost. Dirt channel is 4 gain stages, no CF, 40k cold clipper and plate snubbers - more of an SLO than a Plexi. Boost switch there is cutting lows and adding some gain. Bright switch in the dirt channel affects NFB/presence, Punch switch in off position is a mid cut (!) with lower gain, in on position it also changes the second gain stage cathode values (= structure switch in an XTC). Notable is that dirt channel gain pot is between gain stages 2 and 3, not 1 and 2.

Easy mods IMHO are the addition of presence and resonance pots and a bright cap over the dirt channel's gain pot. If you add a presence pot, you can reuse the bright switch for the cap. I also like a PPIMV, the crunch channel with PI saturation sounds good to me.
 
guyatone said:
I've owned, fixed and modded a couple of these.

It's not a Marshall based amp, nor has it ever been advertised like one. Those expecting a cheap MIC XTC, look somewhere else. That said, it's not a bad amp at all, if you take it for what it is: Clean channel has a Dumble tone stack, clean boost is a mid boost. Dirt channel is 4 gain stages, no CF, 40k cold clipper and plate snubbers - more of an SLO than a Plexi. Boost switch there is cutting lows and adding some gain. Bright switch in the dirt channel affects NFB/presence, Punch switch in off position is a mid cut (!) with lower gain, in on position it also changes the second gain stage cathode values (= structure switch in an XTC). Notable is that dirt channel gain pot is between gain stages 2 and 3, not 1 and 2.

Easy mods IMHO are the addition of presence and resonance pots and a bright cap over the dirt channel's gain pot. If you add a presence pot, you can reuse the bright switch for the cap. I also like a PPIMV, the crunch channel with PI saturation sounds good to me.
Click to expand...
Aside, from the tone stack, what would you say the clean channel is based on? I’ve heard “Fender” but curious which one.
 
guyatone said:
Ne ho posseduti, riparati e modificati un paio.

Non è un amplificatore basato su Marshall, né è mai stato pubblicizzato come tale. Chi si aspetta un MIC XTC economico, cerchi altrove. Detto questo, non è affatto un cattivo amplificatore, se lo prendi per quello che è: il canale Clean ha uno stack di toni Dumble, il clean boost è un mid boost. Il canale Dirt ha 4 stadi di guadagno, niente CF, 40k cold clipper e plate snubber, più un SLO che un Plexi. L'interruttore Boost lì taglia i bassi e aggiunge un po' di guadagno. L'interruttore Bright nel canale Dirt influisce su NFB/presenza, l'interruttore Punch in posizione off è un mid cut (!) con guadagno inferiore, in posizione on cambia anche i valori del catodo del secondo stadio di guadagno (= interruttore di struttura in un XTC). Da notare che il potenziometro del guadagno del canale Dirt si trova tra gli stadi di guadagno 2 e 3, non 1 e 2.

Le modifiche semplici IMHO sono l'aggiunta di potenziometri di presenza e risonanza e un bright cap sul potenziometro del guadagno del canale dirt. Se aggiungi un potenziometro di presenza, puoi riutilizzare l'interruttore bright per il cap. Mi piace anche un PPIMV, il canale crunch con saturazione PI mi suona bene.
Click to expand...


Can you give me more info? i?Can you give me more info on bright and resonance mod?
 
You must log in or register to reply here.
Back
Top