JCM800 Point to Point Part II – Xtra Gain Choices

I bought this 1983 2203 100w head for dirt cheap, but as I opened the hood I was rewarded with a messy inner arrangement, swollen electrolytics, inductors in rlc circuits behind every pot, a ton of relays, 2xel84+2xel34, chassis holes back front and center … your typical ultra modded shit. I had initially tabbed on […]

**SOLD** 1998 MIJ Ibanez RGR570IPT

Rare Ibanez RG570 Reverse in Iron Pewter finish aka RGR570IPT. Made in Fujiken Japan in 1998. Sharktooth inlays. Matching color headstock. Skunk stripe neck. Original V7 S1 and V8 pickups. Very little wear and tear, almost new. Price 420 euros.

JCM800 Point to Point

I bought this 1983 2203 100w head for dirt cheap, but as I opened the hood I was rewarded with a messy inner arrangement, swollen electrolytics, inductors in rlc circuits behind every pot, a ton of relays, 2xel84+2xel34, chassis holes back front and center … your typical ultra modded shit. I had initially tabbed on…

Steve Vai’s JMP and the Laws of Relativity

In 2012 Steve Vai auctioned his personal JMP half stack ¹. The well-maintained 100W head, previously owned by Steve Stevens then modded by Lee Jackson to Steve Vai’s specifications, sports 1 extra gain stage, a tube-buffered FX Loop, KT88 power tubes and a master volume. Vai took it on stage for his David Lee Roth…

Essential Webpages for Amp Geeks

How to design valve guitar amplifiers, from the power supply to output stage and pre amp. http://www.valvewizard.co.uk Greetings and welcome to Uncle Doug’s channel, which features videos about classic vintage guitar amplifiers and circuits, vintage jukeboxes, electronic equipment and devices, handmade steam engines, and technical/instructional presentations. http://www.youtube.com/user/Stratosaurus1 Boutique tube guitar amp Fender Marshall Vox DIY….

Homemade Hot Rod Plexi Part 2 – Superlead vs. Superloud

In the heyday of non-master volume amps, i.e. during the late 60’s, your garden variety 100W amp was designed to blast away on stage without P.A. reamplification and would typically be connected to dark-ish sounding speakers à la Greenback. Think Hendrix at Woodstock. A far cry from today’s typical set up. Back then, a lot…

**SOLD** Two (!) Rare Marshall Tall model 2049 Cabs

The model 2049 cab (2×12″) and 2069 (4×12″) share the same very tall form factor, above 1 meter tall without even including the wheels, and a fairly shallow depth, at least 10 cm shallower than a 1960. They both have excellent projection and were designed to complement the ill-fated Marshall Artisté, which I personally like…

The American Dream

The American Dream perfect embodiment is a self-starter who tweaks computers, electronic gears, music equipment, cars or whatever out of his parent’s house garage somewhere in (South) California and sets out to create a world-renowned industry leader. Disney, Apple, Hewlett-Packard, Amazon, Nike all pretty much originated that way. Randall Smith began modifying Fender Princeton amps in…

Sovtek MIG50 Overhaul

The Sovtek Mig50 is a mid 90’s crossbreed of Bassman and Marshall 1987 packed inside a small format head, with a “Crazy Ivan Approved Heater Circuit™” thrown in for good measure. Talk about Russian engineering. That one must have been designed by a vodka bottle. The Bassman cultural heritage is perceptible in its 0.1µf PI…

Filament Supplies Pre-Wiring

I am yet to find a better way to make a clean layout with the 6.3V AC circuit. By all means do enlight me if you have a more efficient solution. I use a pair of twisting pliers to wrap the leads by the way.

**SOLD** Marshall JCM800 BASS 1551 Cab

The big Kahuna … as big and heavy as an American homemaker. Depth is 5 inches more than that of the 1960B. 18/20mm plywood instead of 16mm. Limited production in the early 1980’s.

Fender MV Silverface Twin bias adjustment

OK, someone brought me this ’72 Fender Silverface Twin w/ Tremolo, Master volume, Celestion GH12H100 speakers and the somewhat useless extra-gain feature activated via push/pull switch on the master volume potentiometer. (For more info visit here). The amp is an absolute best in class pedal platform, and remains astoundingly clean at high volume. The owner actually uses…

First new guitar of 2017

’89 RG560 with original pickups. Really comes across as a superstrat where the RG570 packs more of a metal vibe. Plays very well. Thank you David for the good deal. On a side note I find the Maxon designed V2 to be a totally descent pickups, far superior to the later V series iterations like…

WTF!? Power is OFF & Amp’s Indicator Light is ON

What to do when your amp’s pilot light turns ON as soon as you connect the amp to main power. This is a common issue with older amps in which the power switch opens the circuits only for one of the 2 main power leads. Wiring is as such: Given the extra high impedance of…

RIVERA TBR-1 / PART VI / Schematics

The best I could get. Click the following links to access the schematics files. Please note that there are significant differences in the power amp section between the revised TBR-1 with hi/low power mode & a triode/pentode switch on the back panel and the earlier TBR-1 which have none of these. However I was happy…

RIVERA TBR-1 / PART IV / Accessing the preamp boards

Accessing the top preamp board on the TBR-1 is fairly easy and simply requires removing channel 2 knobs, the board comes out easily. The lower pcb is another story altogether! Here bellow the step by step process: 1. The front pannel cover and its handles have to be unscrewed and removed. As well as 4…

My New Axe

1991 Ibanez RG570 with custom 3-ply pickguard from Perle Guitars, DiMarzio Tone Zone Half-Air Mod (producing way too much bass despite the mod, Evolution II here I come!) & original Edge trem. A very descent setup for less than 300 euros all told. For that low price I had to perform a fret resurfacing myself…

JCM900 Output Transformer Hookup Instructions

The Marshall JCM900’s impedance selector, with its unusual 8 / 4(16) or (4)16 / 8 options has always left me puzzled, until I investigated it a bit and then I got scared retrospectively. How many OTs have been burnt on account of this incredibly sloppy labeling? So here is the info I have been able…

Rocktron Egnater Velocity Valve – Product Manual

QUICK SPECS: For the discriminating guitarist who demands a power amp featuring an all tube design, we proudly introduce the Velocity® Valve. Featuring a design by Egnater Amplification, the Velocity Valve arrives with a solid reputation built on two of the industry’s most highly regarded guitar gear companies. The Velocity Valve features 90 watts/channel built…

Flyback Diodes

From an electronic protection standpoint, soldering diodes anti-parallel to the OT primary winding can save or extend the life of power tubes and/or output transformers by clamping down voltage spikes generated by speaker’s back EMF, sometimes in excess of 3000V at the plates. These spikes can cause electrical arcs inside the tubes and occur especially…

RIVERA TBR-1 / PART III / Product Range Presentation

Also recovered from Rivera 2003 website. Glad to see a list of (in)famous players who endorsed this specific range of rackmount products. Tube Rack Series Innovative, ruggedly built to take the years of abusive road life, and bursting with a wide palette of great tones, each TBR series amplifier is built on a custom basis…

RIVERA TBR-1 / PART II / User Manual

As recovered from Rivera 2003 website & unedited (I did not correct the few typos here and there). Click this link to access PDF version user manual or continue reading bellow.   The RIVERA (TM) Tube Rack Series Stereo Amplifiers Models: TBR-1, TBR-2, TBR-3 (HAMMER [TM] 120), TBR-5 (HAMMER [TM] 320) Users Manual    …

Michael Casswell Amp Demo

Michael Casswell’s demo are, in my opinion, a cut above the rest. Enjoy his take on the recently released Marshall 2555x and Marshall Astoria!

RIVERA TBR-1 / PART I

Bellow some picture of a (poorly) modified TBR-1, first generation, that just landed at my place today. The Pentode/Triode selector might have to go, and the class A / class AB switch – with its bias pot bypass, cathode ciment res & cap – will have to be reworked on account of its general design…

Rocktron Egnater Velocity Valve

This is a rare and apparently much sought after poweramp I just received “as is”. It’s one of the strange fruits stemming from the collaboration between Bruce Egnater and Rocktron Corp. There are very few information online, the manual is in German (of all languages… well after all it’s built like a Panzer Tank). This…

Three Underated Vintage Speakers for Marshall Amps

Rather than investing a month pay in that sweet quad of pulsonic Greenbacks you found on ebay (ever wondered why the seller did not manage to sell them locally?), be on the look out for those wonderfully under-priced numbers. Pictures are from my personal speaker stock. ROLA CELESTION G12M 75Hz 25W BLACKBACK From the later…

Marshall 9005 PT for Sale

Original Drake 120A-1 from 1992 in good working order. Contact me if you blew up ur Marshall 9005 power transformer. I’ll even send you a complimentary 230 Volt fan to prevent this failure from happening again to you.

**SOLD** JMP SUPERLEAD 1976

A big Logo JMP from the late 70’s (bottom amp on the picture bellow). Nice enough amp in good condition except the unavoidable quick and dirty punched-through holes in the back. Sweet clear plastic pots clearly visible – those never fail! Also notice the capacitor mix of mustard caps and plastic films.

**SOLD** Marshall 1960AV

Loaded with 2 V30 and 2 G12H-30. Perfect match, one of the best sounding 4X12 speaker assortment, together with 4 x G12-65 and 4 x Electrovoice EVM12L.  

**SOLD ** JCM2000 DSL 100w

Not a bad sounding amp, it is rumored that Richie Sambora and Paul Gilbert take them on tour, and Lord knows these two dudes don’t take much on tour, especially not their wife or girlfriend. DSL100s are really cheap on the second-hand market here in swinging France, fetching around 350-400 euros. Very full and round…

Homemade Hot Rod Plexi Part 4 – Preamp B+ Cap

Let’s be definitive on at least one issue: a preamp filter cap located inside a small jtm45 chassis is a major source of hum. It is no wonder that the “lower gain” jtm45 and early plexi50w have it on the board, while every “higher gain” mod.1987 from the mid70’s onward have it on the chassis…

DIY True Bypass Looper

This type of homemade looper will set you back a mere 40 euros, roughly 1/5th of the commercial alternative available. The one pictured bellow currently sports 3 x true bypass loops, 1 x a/b box (between loop2 and loop3) and 1 x channel select. As its layout is constantly being changed, the Hammond chassis is…

LPB-1 Booster

The EHX LPB-1 booster is a simple general purpose boost that affects all the guitar frequencies with its .1 uf coupling caps. Quite the opposite from a treble booster it sounds more like a “bottom” booster or a +15db buffer of sorts. On its own,  it comes across as a somewhat usefull device that improves…

Homemade Hot Rod Plexi Part 3 – Snubber Caps

Snubber capacitors in parallel with each rectifier diode will go a long way towards reducing the high frequency parasitic oscillation in some tube amps by bring down the diode switching noise. Typical values range from 1nf to 47nf. Coupled with relocating the bridge rectifier on the far side of the chassis, this has had a…

Homemade Hot Rod Plexi Part 1 – Presentation

I embarked on a homemade 50W English-style head “from scratch” project a few weeks ago, and I managed not to blow things up entirely, which is quite a feat considering the amp was built mostly with parts laying around i.e. an OT and a choke scavenged from a 1976 JMP, JTM45 reissue PT, unmatched carbon…

**SOLD** Marshall JCM800 Superlead 100w

A rare 100W model 1959 Superlead in JCM800 format, from 1983! Well preserved and fully functional. Punchy and very very loud amp! Clean PCB, no modification. 2 holes drilled on the back-panel that correspond to a FX loop which has now been removed.  

**SOLD** JCM800 2203 + Rare 400w Cab

A beautiful half-stack, with matching brown grillcloth (discolored black grillcloth that is, and this only happens with JCM800). While late 80’s horizontal inputs 2203s are usually all but remarkable, the cab is much more worthy of interest: a JCM800 1982B Cab loaded with 4 x 100w Celestion G12h-100. Huge bottoms and very straight sound, not…