Frames Index
Guitar amplifiers:
Hiwatt Custom 100
28/4 1998 Jarmo Haapamäki
This can be read on the Audio Brothers' Hiwatt Custom 100 page on http://www.audiobro.u-net.com/dr103.htm: (the picture is from their site, too. There's other pictures as well there). Audio Brothers is the company that builds the Hiwatt amplifiers today.
The Custom 100 head is the real thing!! Used over the years by Dave Gilmour, Pete Townsend and countless other rock icons, this is a faithful copy of the original Dave Reeves designed amp head of the mid seventies.
With an output stage of four EL34's running at 60% class'A' it effortlessly achieves that loud clean valve tone that made HIWATT the 'Rolls Royce' of British guitar amplifiers. 100 Watts of pure valve power into one or two SE4123 loudspeaker cabinets is easily enough to project you above the loudest drummer in most medium sized venues.
It actually can be bought today, they have started to make them again. Before that, the only "good" Hiwatt heads were made earlier than 1982. I think Dave Reeves passed away then and the young geniuses at the factory started to experiment with transistors (!) and printed circuit boards and the overall quality fell.
My Hiwatt is made in 1980, wired by Harry Joyce (his wrote his name in the inside of the amp with a blue pen). I bought my amp secondhand around 1991 from my friend Rainer Tuppurainen, who had bought it from Lars Carlsson, here in Hälleforsnäs. Lars had bought it from Dan Östberg, I think. Before that I don't know.
Nobody seemed to appreciate the quality and sound of the Hiwatt. They didn't know what they had. Well, it wasn't the amp for the eighties, when rock'n'roll was U2, Simple Minds and The Cure. But I enjoyed the loud pushy sound of the Hiwatt right away. I didn't have to pay any money for it. I had an old type writer and an old little video recorded I didn't need. Rainer got those, I got a marvelous guitar amplifier.
What I like the most about Hiwatt is that's there's not really need to change any settings when you want to play clean and then overdriven again. With vintage Celestion speakers (I haven't tried any other good speakers, the 80's Celestions sucks) - you just play your guitar very gentle and you've got clean sound, hit a power chord and you've got that marvelous nasty Hiwatt rock'n'roll sound - and it really moves some air!
I have heard that Hiwatt's own 4X12 cabinets with Fane speakers would really kick some ass, but I have never had the change to test one. I hope I can do it some day.
I don't use my Hiwatt for the moment. It's dead. I have planned to change every detail of it (inside) that is worn down or broken: all the tubes, potentiometers, capacitors etc. You can still buy about every tiny detail to it, thanks to the fact that it's still under production. The complete from the Audio Brother's Hiwatt internet page I mentioned in the beginning of this article.
I'll get back to you when I'm done and tell you how it went. Did I loose some of the great sound of an old Hiwatt or does it sound better? Did I get it work? Did it blow up? Bookmark this page and wait for the answers...
What amp do I use for the moment? Laney VH100R. Actually I'm not missing the Hiwatt that much...
3/5 1998 Jarmo Haapamäki
How does it go with trying to give a kiss of life to my Hiwatt? Well, for now I'm trying to a little information first before I start to operate. For starters, I sent an e-mail to Steve Gibbs at Audio Brothers, the Hiwatt manufacturer of today. I told him want I wanted to do and was quite surprised that the fellow answered me i a day or two. On a Sunday...
This is what he wrote:
Hi Jarmo,
If your Custom 100 has Hylight Electronics on the back it is earlier than 1982 and is one of the collectable ones. They don't usually need the kind of radical attention you are suggesting.
I think that all you would need is a properly matched and balanced set of output valves. All 4 need to be matched, and chosen to suit the amp, as it has no bias adjustment.
If it is one of the later amps made with printed circuits inside it would be very difficult to change components anyway.
Please tell me everything that is on the backplate, both printed and stamped, so that I know what we are dealing with, and can recommend the best course of action.
Steve Gibbs
I replied him right away. Here's a shortened version of my (too) long mail to the guy:
There's a sticker inside my Hiwatt saying TESTED DATE "22/5/80", so my amp was tested and ready to be shipped to Sweden in May 22nd, 1980. The back plate says following:
- HIWATT AMPLIFIER
- Made in England by
- HYLIGHT ELECTRONICS (HIWATT AMPLIFIER) LIMITED
- TYPE "AP"
- MODEL No "DR103"
- SERIAL No "14697"
I've heard that capacitors get older after about ten years and starts to leak. Does it do something to the sound quality of the amp? Shouldn't at least some of them to be changed for now, the amp is almost 20 years old...
I think I must change something else besides the tubes. The two inch long blue resistor near the fuse holders has kinda melted, it has bubbles on it and it has earlier loosened from the circuit board. I think it says W22 470R 5% on it, the text has almost faded away.
The shorter resistor next to the melted one (W22 100R 5%) looks OK to me, as well as every other parts I can see. Do you think I have to change more parts or is it enough if I change the melted one? Maybe you know (a can make a good guess) what has happened inside my amp?
The melted blue resistor has looked that way for ages before the amp went silent. But I think the the amp has lost some of it's power and the sound has been more distorted that it used to be. It's hard to say, cause there's hasn't been a sudden change. I loved the sound, though. It was really rocking.
I want to be able to trust my amp, that's why I told that I plan to change the works, the capacitors and potentiometers too while I'm at it. But if you think it doesn't improve my Hiwatt amp, I'll just change the necessary parts.
Jarmo Haapamäki
I also asked him about Harry Joyce, who this guy was and also of a cable inside my amp that has loosened and I don't know where it should be connected. Now I'm just waiting for Steve Gibbs to answer my questions.
9/5 1998 Jarmo Haapamäki
Steve Gibbs from Audio Brothers didn't really answer my questions. This is what he replied:
What you describe is not like the standard wiring of a DR103. Do I have your address? Send it anyway and I will send a schematic for you to trace the wiring.
We can sort this out between us - keep writing.Steve
Now I'm a little confused. Not the standard wiring? I sent him my address and we'll see how it goes. Well, he said that we can sort this out. I hope so.
I like my amp.
- Some technical data...
- Hiwatt Custom 100 (DR103)
- Input line voltages : 100V, 117.5V, 225V, 250V a.c.
- Power consumption : 330 Watts (maximum)
- Fuse ratings : Mains (100V, 117.5V) - 6.3A (T) slowblow (225V, 250V) - 3.15A (T) slowblow
- H.T. (100V, 117.5V) - 3.15A (T) slowblow (225V, 250V) - 3.15A (T) slowblow
- Output valves: 4 x matched EL34 (6CA7)
- Preamp valves 3 x ECC83 (12AX7) (7025)
- Preamp valve 1 x ECC81 (12AT7)(6201)
- Output power : 100W RMS (min) into 8 Ohms
- Loudspeaker input impedance : 4, 8, or 16 Ohm
- Dimensions : Width - 640mm Depth - 288mm Height - 269mm
- Weight : 20.5Kgs
sound samples
If you want to hear how a Hiwatt sounds, check out
The Soul Preachers sound files, the guitar is a Yamaha SG-2000.
- .visitors on this very page since November 16th, 1997.
- Webmaster: Jarmo Haapamäki (Sweden)
