Trace Elliot GP7SM Bass Amplifier - Comprehensive Guide

Summary

In this video, Paul takes a deep dive into the Trace Elliot GP7 SM bass amp, sharing his personal history with the amp, including his first experience with the GP7 SM 130 combo in the '90s and the journey of replacing it with a 250-watt version. He discusses the repairs he's done, including fixing a buzzing sound caused by a loose preamp connector and replacing a faulty fan. Paul also breaks down the features of the amp, such as the 7-band EQ, DI out, and effects loop, and ends with a sound demo, showcasing its punchy and versatile tone.

Takeaways

• 😀 The Trace Elliot GP7 SM series of bass amps were introduced in the early '90s as a replacement for the Series 6 amplifiers.
• 😀 The GP7 SM series is significant to the speaker as it was the first amplifier he purchased in the mid-'90s.
• 😀 The speaker recalls buying the GP7 SM 130 combo in Birmingham, UK, for around 480 pounds (nearly 600 pounds with trade-in).
• 😀 The GP7 SM amps come in various power configurations, including 130W, 150W, 200W, 250W, and 300W models.
• 😀 The speaker had to fix a buzzy noise issue in a GP7 SM 250 amp, discovering a poorly installed fan and loose preamp connector.
• 😀 The speaker advises that a change in sound due to tapping an amp could indicate a loose connection, not necessarily a need for a capacitor replacement.
• 😀 He uses a simple fix of a glue gun to secure loose connectors in the amp to avoid further issues during gigs.
• 😀 The GP7 SM 250 amp has multiple features, including input gain, passive/active input switch, pre-shape buttons, and a seven-band EQ.
• 😀 A balanced DI output allows for pre-eq or post-eq options when sending a signal to a PA system, giving flexibility to musicians.
• 😀 The amp has an effects loop, EQ balance control, line out, and a mute function that is useful for switching instruments during gigs.
• 😀 The rear panel includes an on/off switch, mains fuse, and a ground lift option to address potential earth loop issues in the equipment.
• 😀 The speaker also provides insight into the inner workings of the amp, including a toroidal transformer, pre-amp board, power amp section, and a new fan for cooling.

Q & A

What is the significance of the Trace Elliot GP7 SM bass amplifier to the speaker?

The GP7 SM is significant because it was the first amplifier the speaker bought in the mid-90s. It replaced a Peavey TNT 100 and was an essential part of the speaker's early musical career, both in the UK and later in Australia.

What was the initial issue with the Trace Elliot GP7 SM amplifier when the speaker purchased it?

When the speaker first purchased the GP7 SM amplifier, it had a buzzing noise, which was caused by a loose connection. The problem was resolved by reseating the preamp connector and using a bit of glue to keep the connection secure.

What is the purpose of the fan inside the GP7 SM amp, and what issue did the speaker encounter with it?

The fan in the GP7 SM amp is designed to keep the amplifier cool during use. However, the speaker encountered a problem with the fan, which was replaced with a new one after discovering that the previous fan was a makeshift PC fan with resistors attached to slow it down.

What is the function of the 'pre-shape' button on the GP7 SM amp?

The 'pre-shape' button on the GP7 SM amp allows the user to select one of two preset EQ shapes, altering the overall tone of the amp. It is part of the signature Trace Elliot sound, providing easy adjustments for bass tones.

How does the speaker adjust the tone using the EQ on the GP7 SM amp?

The speaker uses the seven-band graphic equalizer (EQ) to adjust the sound, typically keeping all bands set to zero dB for a neutral setting. Adjustments are made based on room acoustics and specific tone preferences, such as tweaking bass or mid-range frequencies.

What is the DI output feature on the GP7 SM amp, and how does the speaker use it?

The DI (Direct Injection) output on the GP7 SM amp is used to send the signal to a PA system. The speaker prefers using the built-in DI rather than a sound engineer's DI box, as it allows the sound to be colored by the amp settings.

What is the purpose of the effects loop on the GP7 SM amp?

The effects loop on the GP7 SM amp allows external effects to be inserted between the preamp and power amp sections, providing more flexibility in applying effects to the signal before amplification.

What is the significance of the EQ balance control on the GP7 SM amp?

The EQ balance control on the GP7 SM amp adjusts the frequency pivot point of the graphic EQ, allowing users to either increase the top end and decrease the low end, or vice versa, depending on their tonal preferences.

What is the difference between the 'RMS' and 'peak' power ratings for the GP7 SM 250 amp?

The 'RMS' power rating refers to the continuous power output of the amp (250 watts), while the 'peak' power rating indicates the maximum transient output the amp can handle (500 watts), which is typical of Trace Elliot amps that are conservatively rated.

How does the speaker feel about using combo amps versus amp heads like the GP7 SM?

The speaker prefers using amp heads over combo amps, as they are more versatile and easier to transport. They had two GP7 SM combos but decided to sell them, keeping the amp head for convenience and space-saving purposes.