the Landry 100 watt amplifier in our workshop

the Landry amplifier

the Landry amplifier

Hello again. We are now offering world-class (non-warranty) service and repairs to Landry amplifiers of St. Louis, Missouri USA. We should point out that we have no official relationship with Landry amplifiers, so we cannot accept any warranty repair claims without the endorsement of Landry or their Australian sales representative. The Landry amp is a relative newcomer to the boutique guitar amp scene. We endorse the fact that these amps are totally valve (tube) circuitry (apart from solid-state rectifier), and are completely hand-wired and assembled, presumably by one person.

the Landry amplifier

the Landry amplifier

Landry are producing only one or two models, very obviously voicing their amps towards the classic British/Marshall sounds (in both channels), but with a number of enhancements and more modern high gain sounds available as well. There are two independent preamp channels, each with its own 3-band passive EQ. The ‘clean’ channel is voiced similar to a JTM45/Bassman style amp, and the ‘distortion’ channel is voiced similar to a JMP series amp, but with additional gain available via a footswitch. After the channel switching takes place the signal is routed via a valve-driven series FX Loop.

the Landry amplifier

the Landry amplifier

The master volume is of completely conventional design, following after the FX Loop, but works very effectively in this amp design. The big surprise in a Marshall inspired amp such as this, is the inclusion of a valve (tube) driven reverb of very acceptable sound quality. Certainly much better than the reverbs ever were in Marshall amps over the years ! The phase inverter, power amp and power supply stages are very similar to what you would find in a 100 watt JMP Marshall.

Landry turret board and hand wiring

Landry turret board and hand wiring

The power and audio output transformers are in fact the very excellent 100 watt JMP style models by Classic Tone/Magnetic Components of Chicago USA. The claim on the Landry website that the ‘clean’ channel delivers sparkling blackface tones is of course an exaggeration. This channel delivers the fatter JTM45/plexi/’59 Bassman type tones, and there is absolutely nothing wrong with that at all.

setting the bias on this amp is very easy

setting the bias on this amp is very easy

Our good customer, Steve Edmonds brought this 100 watt head into the workshop last week, stating that the amp had lost some of its magic. Please see our post of 25/2/2014 re the Steve Edmonds band, and new project Mescalero. Inspection of the chassis revealed no apparent problems, but testing all the valves (tubes) separately from the amp did reveal most of them were in a degraded state, suffering from microphony, low gain, etc. Apart from a Tung Sol (reissue) 12AX7 in position V1, all other valves (tubes) were Chinese 12AX7B and EL34B. Now this amp is really only a few months old, but Steve is currently the hardest working guitarist we know, generally playing four gigs per week.

Landry chassis: six preamp valves in total

Landry chassis: six preamp valves in total

As a sweeping generalisation, Chinese manufactured valves (tubes) can quite often sound very good indeed when brand new, but can also lose their quality relatively quickly. Their 12AX7’s especially seem to become not only microphonic but also rather harsh and brittle. No doubt they will improve their quality of manufacture over time, the Russians certainly have. We installed a mixture of JJ, Electro-Harmonix and Tung Sol (reissue) valves, pre-tested and graded in our workshop, making an effort to select the ideal valve for each position. For the output stage we installed a matched quartet of Tung Sol EL34B, which have been certainly the most reliable of current production EL34’s (in our experience), although they do sound different to other EL34’s – therefore the customer’s personal tastes have to be taken into account in these situations.

the Landry chassis

the Landry chassis

Rebiasing the Landry for new output valves is easy and convenient – I wish the major manufacturers would take note ! All four EL34 cathodes are connected together to ground via a 1 ohm/10 watt resistor, which in turn is connected to external DVM test points. Simple ! The amp passed its power output and burn-in testing with flying colours, and it seems that Steve is very happy with what he was hearing at last week’s rehearsal. Many thanks to Steve Edmonds for his continued support and for supplying us with the subject matter for this blog. IR.

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