Image description




Audio & Music Equipment Repair      Custom-Design   ●   Valve Amplifier Specialist 

Service & Repair

Here at Astral Sonic Technology, all repairs are carried out down to component level, aided by our extensive database of technical service information and direct links with technical departments of commercial manufacturers. This ensures that faults are correctly identified and repaired properly.

Our Final Test procedure consists of a very comprehensive set of technical tests, as well as real-life sound tests to ensure that the equipment actually performs as it should, according to manufacturer's specifications, and does so reliably.

Only after all our stringent tests are passed, is equipment released for collection, complete with a full Service Report and a minimum guarantee of 90 days on workmanship.


We carry stocks of a wide range of components, which helps us to provide a fast turnaround.

We use either new original components from the equipment manufacturer, or quality replacements that meet or exceed original specifications, and we can usually locate even the most hard-to-get or obsolete components.

When selecting components for certain types of equipment, such as valve-based or vintage equipment, we also take into account the nature of the circuitry and how the overall sound may be influenced by the particular characteristics of different types of components

We will liaise with you to ensure the best choice is made.

Astral Sonic Technology service, repair, restoration

Valve Amplifiers and other Valve-Based Equipment

We specialise in the repair and servicing of all kinds of valve amplifiers, and other valve-based equipment, of any make and any vintage.

We have extensive in-depth experience in servicing, repairing, refurbishing and rebuilding a wide and varied range of valve amplifiers, backed up by our ever-expanding database of technical service information.

Each and every amplifier is worked on with care and consideration, and any replacement components are carefully selected to match the particular equipment where appropriate, especially in the case of vintage/rare equipment.

Once repair work is complete, each amplifier is carefully set-up for optimum performance, before undergoing a very comprehensive set of tests.

Finally, sound checks are carried out using guitars and/or recorded music to ensure the equipment actually performs as it should, and reliably.

Valve amp service, repair, restoration
Valve amp service, repair, restoration

Our Service Procedure

We carry out all repair work systematically and methodically to ensure we correctly identify all issues, and to ensure repairs are then carried out successfully and efficiently. The time spent, and hence cost, is kept under control.

Fault-finding is largely a process of elimination, so it is crucial to first carry out basic checks and tests before homing in on the problem-area(s). To this end, all equipment undergoes the same detailed procedure of work.

Step 1

Booking equipment in

Upon receiving your enquiry (phone, text or email), we will discuss the issues the equipment exhibits and arrange a day and time for it to be brought in to the workshop, as well as charges for Service & Diagnostics.

Step 2

Service & Diagnostics

A wide range of very detailed measurements and tests are carried out, including safety checks, inspection, cleaning of dust, wiring and connector checks, resoldering of accessible poor solder joints, contact-cleaning, tightening of fixings, detailed component measurements, functionality tests, measurements of voltages, noise levels, signal flow and frequency response.

After Service & Diagnostics is complete, we will then let you know what repair work is needed and costs, including options for non-essential work, if applicable. The repair work to be carried out would then be agreed.

Step 3

Repair work

All agreed repair work is carried out. Any issues or delays that may arise which affect cost or time taken will be brought to your attention as they occur, before proceeding.

After all repair work is complete, the equipment is set up for optimum performance, ready for Final Test.

Step 4

Final Test

The Final Test stage consists of a comprehensive range of tests and measurements which include (where applicable): output stage balance & bias, bias stability, functionality, frequency response, maximum output power, stability under high power output conditions (“power soak”) and sound checks (using guitar and/or recorded music).

If no issues arise, then the equipment is prepared for collection.

Step 5

Collection of equipment

As soon as the repaired equipment has passed Final Test, we will contact you to arrange a day and time for the equipment to be collected and to agree final payment arrangements. Upon collection and receipt of payment, you will be issued with a formal Receipt and Service Report. We will archive copies of these, together with all recorded repair/test notes for when the equipment is back in for servicing.

Step 6

Future servicing

Electronic equipment benefits from regular Servicing in order to ensure continuing performance and to avoid potentially costly repairs. You are encouraged to return equipment in 12 months' time for Servicing.