HAMSTEAD SOUNDWORKS
A pair of unsuspecting Cambridgeshire-based industrial units play host to a rising force in British hand-built guitar amplification – Guitarist pops into Hamstead HQ for a cuppa…
Like many great ideas, the beginnings of Hamstead guitar amplification, just four years ago, can be put down to pure chance. Peter Hamstead had made his first amplifier as a project back in the 1960s when he was an apprentice, but went on to have a career in avionics, specialising in electronic design and development for the aircraft industry. After striking out on his own, a new neighbour by the name of Jim Bird moved into the unit next door to him, noticed some electronic test gear in his workshop and asked Peter if he could repair a guitar amplifier. “I said, ‘We can make them if you want.’ That’s really the beginning of it,” says Peter, as we settle down for a chat in his workshop. “Then, as a part-time thing, just a few hours a week between us, we developed our first amplifier. We got to the stage where I stopped doing everything else and started just manufacturing guitar amps.”
With Peter’s career in a different side of the electronics industry, we wondered if the transition to the world of rock ’n’ roll was an easy one. “Because I’d been doing design and development work, not just avionics, it gave me a good grounding, really, for guitar amplifiers. Jim just said what he wanted and I worked out how to do it. Then we just did some voicing. He would come in for an hour or so every week and we would change things. During the first few years doing it part-time, I learned a lot about guitar amps… and guitarists.”
DRAWING ON EXPERIENCE
During the course of making the first Hamstead amplifier, Peter found some established practices in design that he chose to improve upon. “I looked at a lot of the traditional amplifier circuits to see what people were doing to get the different sounds and effects,” he says. “And then decided that some of the things were good, some things I didn’t think much of. So I started with a clean sheet of paper and just drew something out how I thought it should be. It was almost there straightaway, you know, the sound that Jim wanted.”
What, in laymen’s terms, were the things that Peter thought he could improve upon? “I wasn’t keen on the idea of having a presence control that was part of a feedback loop in the output stage, because if you start putting feedback into an output stage – or any stage of a guitar amplifier – it does reduce the gain. It reduces distortion, but what happens is, if you start to drive that output stage hard, so that it starts to go into saturation, you suddenly lose the feedback. You get a sudden change in sound, relatively, whereas if you don’t have any feedback, you get a nice smooth transition from clean into overdrive. So that was one of the things I wasn’t happy about, having feedback. Our output stages don’t have any feedback at all and no presence control.”
We’re curious as to what Peter considers to be the tonal centre of a good valve amplifier. “I think it’s a bit of everything,” he says. “There’s a little bit of local feedback on the first stage, which is not a problem because the first stage never gets overloaded, so there’s not a problem with the feedback. The phase splitter has a big effect on the sound and I think the other thing, really, is we use a relatively large output transformer that has been wound to my spec to be as clean and as transparent as possible, so that it has as little effect on the sound as possible. A lot of old amps, they have very small output transformers.”
“As a part-time thing, just a few hours a week between us, we developed our first amplifier”
In what way does the effect show up in the voicing of the amp, exactly? “If you want to change the voicing of the amp, then you will have a major problem if you have a small transformer,” Peter affirms. “However, if you have a large one that is transparent, you can then change the components, resistors and capacitors around the circuit to change the voicing easily and that’s what we did. So we’ve done that with the Artist 20 and the 60; we’ve got rather large output transformers, which does make them a bit heavy, but people always say they sound great, so we’re obviously doing the right thing.”
POWER UP
After the Hamstead Artist 20 had made its impact on the guitar world, Peter stepped up the power a little for the Artist 60 (reviewed in full on p18 of this issue). What was the thinking behind the larger amp? “Clean headroom,” he says. “The preamps are the same. The phase splitter onwards does run at a higher voltage. The 20 is cathode-biased, whereas the 60 is fixed biased. I don’t like that term ‘fixed-biased’, because it’s not, it’s adjustable, which I find amusing, but never mind, I’ll go with it. Yes, it’s fixed-biased because otherwise you wouldn’t get 60 watts out of a pair of EL34s; you’d need four or six of them to do that and that’s a bit silly, really. They’d start getting heavy.”
Are there plans to increase the power any further in future Hamstead amps? “No, down the power. Five, seven… These have got power switches on the back,” he says pointing to the Artist 20 and 60 amps on show where we’re sitting. “If you did something like a seven watt, it could do two and probably 0.5 watts.”
Pedals form another side of the Hamstead Soundworks empire – the company has already put out an analogue tremolo pedal and the Odyssey Intergalactic Driver, designed as the Swiss Army knife of all drive pedals. General overseer in this area, as well as being another safe set of ears for the amp voicings, is Tim Steer. “I started off wanting to learn about guitar pedals and just popping in every now and again to do some assembly work and just to see what was going on,” Tim tells us. “That sort of developed into an R&D role, really. I still do pedal manufacturing, or assembly, but really, it’s developing new products that takes up the bulk of the time.”
Tim’s background is playing in bands and doing session work. “I’ve spent more than 10 years playing for lots of different artists, having a lot of fun doing that, meeting interesting people. Also, doing production and songwriting, so I spent a lot of time in the studios listening to things critically and trying to develop my ear. It’s all those sorts of skills that I try to apply to stuff now.
How did the development of the Odyssey begin? “We were very sceptical of doing a drive pedal to begin with, just because there are so many on the market. We didn’t want to copy anything else – we didn’t want to do a version of a Klon or a Blues Breaker or anything like that. I was doing a lot of studio sessions at the time and taking 10 to 15 different drive pedals with me and sometimes I’d think, ‘Oh, that one I left at home was the one I actually needed.’ But the big thing was workflow. You’d be halfway through recording a chorus and
The Odyssey Intergalactic Driver is designed as the Swiss Army knife of all drive pedals
think, ‘Actually, no, that pedal sounds better. Just hold on, I’ll just unplug everything and plug in the new one.’
“So could we create an overdrive pedal where I could go to a studio session and it would cover everything that I needed? And could I do four different gigs for four different artists from pop to alternative rock or whatever, and the same pedal could stay on the ’board for all of these gigs?”
So, where was the actual starting point for the Odyssey? “We looked at it literally from the output jack. What does the amp see from a pedal? The initial design started off with probably 12 knobs and 18 switches, and then we tried to force it down into as compact a form as possible. A lot of it is just manipulating the circuit that’s in there. The input gain stage is very important; the pre-and post-switch is very important for creating those sorts of sounds.
“For example, if you put five times your guitar’s output through a circuit and then boost 18.5dB of bass through it, going into the drive circuit, you get a very square wave that starts to cover all your fuzz territory. Similarly, if you then put that post the drive circuit, you get a much more studio-style EQ, so it just scoops out at all the mids and you get a metal sound from the flick of one switch. Then if you want Tube Screamer sounds, it’s active EQ instead of passive, so you can very easily cut the mids either before or after the drive circuit. So you can get a myriad tones out of a few controls. At least, that was the idea.”
The pedal was so successful in achieving its ‘master of all’ status that a bass version is about to be released. “We basically took the concept of the Odyssey and came at it with a blank sheet – what do we have to do to this to make it work for bass? Basically, we revoiced it. The drive breaks up at different frequencies and the frequency response is different in the tone stack, and we added a parallel clean boost as well. A lot of bass pedals use clean blends, so you split the signal across the pot and you have 100 per cent in one and 100 per cent of the other the other way and 50-50 in the middle. We didn’t really like that idea because you end up sacrificing one as soon as you turn towards the other. So we implemented a parallel clean pot, so your signal splits at the beginning: 100 per cent goes to the drive circuit and 100 per cent goes through the clean pot as well, which has a two-times boost. You can blend 100 per cent of your drive signal with 100 per cent of your clean signal and both are isolated from each other, which made a good difference sonically.”
EXPANDING HORIZONS
Just as the company’s amp range has grown, the pedal section of the business is set to expand, too. “Yes, we’ve definitely got some other stuff on the horizon,” says Tim. “I don’t know how much I can talk about…”
From what we can ascertain, there are going to be some exciting pedal-based announcements from Hamstead in the new year, so watch this space. But the final word must go to Peter, the design force behind both pedals and amps. We wonder how he feels about his creations? “I only design them and make them. I just get led by Jim and Tim. If they like it… it’s as simple as that,” he reflects. “I must admit, I do know when they sound right.”
“Could I do four gigs from pop to alt-rock, and the same pedal stay on the ’board for all the gigs?”