HH Amplifiers

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A selection of HH PA and Power Amps
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Link to an eBay page
A selection of HH PA and Power Amps

A Buyer's Guide

For those that are interested in the '70s and '80s versions of these amps, there always seems to be a fair selection of them advertised on eBay. Many of these are very sensibly priced, bearing in mind that they are 30-40 years old and, without some maintenance or repair work, are unlikely to be reliable, or even work. However some are priced as if they were as rare as hen's teeth (which they are not - there are hundreds of them out there) so it will pay you to do a search of the sold items listings to get an idea as to what a fair price might be. For example I've seen untested MA 100 PA, S130 Slave and IC100 Amps  sell for as little as 99p in the real world, yet some sellers think that their untested 40 year-old amp is so rare as to be worth hundreds (they're not!).

However, these were, in their day, some of the best transistor amps you could get as they were clear, reliable, and VERY loud (albeit it a bit 'hissy' by today's standards). I've used nothing but HH amps for PA and keyboards for the last 30+ years, and they've rarely let me down. However if you are considering buying one then there are a few caveats that are worth considering...

A lot of the amps for sale will still have their original electrolytic DC smoothing capacitors, and on almost every one that I've seen over recent years these are usually slowly breaking down, even if this is not visible to the naked eye.  Where it is  visible then they are often bulging, and leaking electrolyte, which is toxic and corrosive. It is also conductive, so if any drops onto one of the circuit boards it could cause a short-circuit and fry the board (or worse!). If they are in poor condition then they may also not be doing their job properly, i.e. maintaining a constant, smooth 50v DC current to power the amp, and could thus cause damage to its components.

I use nothing but MA, MXA and S series HH amps, and the first thing I do when I get a 'new' one is to replace the DC capacitors immediately unless I know, for an absolute fact, that they have been renewed recently. Failure to do so could end with a fried amp, and result in you being a very unhappy buyer, particularly if the seller has a no-returns policy. The same thing applies to any other old amp, so I therefore do the same job on any one that comes my way, be it an HH, Carlsboro, Custom Sound,  or whatever.

IMPORTANT NOTE: replacing the capacitors is  NOT  a job for those who do not know what they are doing. Even when switched off and unplugged from the mains, amplifiers can have LETHAL voltages stored within them. So, unless you are qualified, NEVER remove the top or bottom cover plates, and always entrust any job to a professional. Changing the capacitors is not a long task, and shouldn't cost more than about £25-30, including parts. However it might be worth building this cost into your budget when bidding on these amps.

Another issue is that if the amp has not been stored properly, such as having spent the last decade in a shed or garage, then there may be corrosion to the inputs and outputs, fuses and fuse-holders, and various other components. These can prevent the amp from working properly, even if it is otherwise fit for duty. However an electronics engineer will be able to clean these up and ensure good electrical contact is restored, although this would result in more expenditure. Also, crackly pots (potentiometers - the things behind the knobs which you can't see from the outside) are almost inevitable in amps of this age, but they will be far worse if storage has been poor, and cleaning them can be time-consuming, and replacing them is expensive.

To sum up, I thoroughly recommend these old amps for amateur and semi-pro use, but please don't pay too much for them, and bear in mind that a new 200w stereo power amp will cost little more than £60. However if you've just bought an HH then please get it checked by a professional before you use it. A little investment now could save you your purchase price, and get you a great amp that might last for another 35 years!

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