My Hiwatt dr103

[TheAviator]

Hi All,

I just brought a Hiwatt dr103 from somebody who brought the amp back in 1973. He is the original owner and paid £95 new on the 24th April 1973 , including a set of Bass string. He has used the amp, trouble free, all this time as a bass amp. He told me that the workings are all original including the valve which are all Brimar.

The amp is very clean and in very good condition, I tried to upload some pic's but the max file size is 512kb. I'll try to reduce the size somehow and post them later.

Did some Hiwatts come with Brimar valves installed instead of Mullard? Also is it worth me replacing them due to their age?

Compared with my old hiwatt dr103, which was from 1975, it sounds a bit more harsh and has a lot of middle in the sound, so much that I keep adjusting the middle down to less that nine o'clock, is this typical or have I got too used to Fender twins? I am currently using a Marshall 1960 loaded with Celestion gt12-75s, I know this is not ideal but will switch to a Fane type as soon as I can afford to.

Sorry for all the questions

Thanks

The Aviator

[Dr.HI-TONE]

Brimars could have been original. They are great valves. To my ears they can be a bit more aggressive sounding than Mullards.

12g75t speakers are one of the worst to mate with a HIWATT. I would not use them when making any decision related to tone.

[OldSchoolDave]

Congrats on the acquisition! Looking forward to seeing the pics (hope you can understand, if we allowed lots of very large files to be posted, the board's database could bog down - and we want to keep it nice and snappy ).

I agree with Dr.Hiwatt's comments and would only add that if you do decide to experiment with different valves, concentrate on V1 first. It has the most impact on tone. If those BRIMARs are original (which they could be), they could be getting tired by now.

Dave

[TheAviator]

So I guess I dont have much to lose by trying a new set of valves, I can alway replace the old ones if need be. Has anybody got any recommendations on which valves to buy? I'm looking for...you guessed it, that GIlmour sound as I play in a Pink Floyd tribute band.

TheAviator

[Dr.HI-TONE]

bang for the buck........I like JJ ecc83 for new production valves.

[OldSchoolDave]

bang for the buck........I like JJ ecc83 for new production valves.

Ditto. And, if you happen to have a NOS ECC81/12AT7/CV4024 laying around (which are, thankfully, much less expensive than ECC83's), try that in the PI socket.

Dave

[TheAviator]

It currently has a Brimar ECC81 in the PI position. I read somewhere that you can use an ECC81 or ECC83 in this position, what difference does this make to the sound of the amp?

Here are some pics.

[TheAviator]

Can anyone tell if any components are not original. How about the filter caps?

Thanks

The Aviator

[Dr.HI-TONE]

it is very nice.
a quick glance did not reveal anything unoriginal to me.

I used to own #3940 and it was identical internally. That is untouched, but would benefit from a cap job.

[TheAviator]

Thanks OldSchoolDave and Dr Hiwatt for taking the time to answer my questions, your knowledge on these amps is invaluable to me and many others using and viewing this forum.

I think I was lucky here, the guy I brought it off was the original owner. It served him without trouble for almost 40 years, I cant imagine any modern amp doing the same.

It was on Ebay for £1200 and nobody brought it. He put it up again for £1100 so I borrowed the money from my boss and snapped it up.

It doesn't sound as nice as the 1975 DR103 I owned, I'll change the valves and filter caps as you suggested. Do you think the filter caps are original? Do they make a difference to the sound?

Thanks

The Aviator

[Dr.HI-TONE]

they are the original caps.
they do affect the sound. I notice less noise and a firmer more powerful tone after a cap job.
The amps usually seem less "tired" afterwords.

[TheAviator]

Just took the Amp to an local Technican, he confirmed that filter caps needed replacing, he showed me that they are leaking out the bottom. You can just see it in the picture if you look at the cap under the diodes, and the cap next to it. He also said that he would check the output valves as they probably need replacing by now. For starters hes going to replace V1 with a good Mullard that he has lying around.

[OldSchoolDave]

He also said that he would check the output valves as they probably need replacing by now. For starters hes going to replace V1 with a good Mullard that he has lying around.

That's a good start. Make sure to ask for your old valves back... Not much sense in saving old filter caps, but some folks do.

Dave

[TheAviator]

I got my Hiwattt back from the amp tech, he replaced the filter caps, and loaded the output valves with Tung Sols and replaced the preamp valves with a mullard ecc83 in V1, Mullard ecc81 in P1 and Tung Sol 12ax7's in the remaining slots. I must say the amp is now a completly different beast, and sounds incredible. Already played two gigs with her, this amps on another planet.

I have a question on the V1 valve. Can this first input valve by easily damaged by overloading the input with pedals that boost the guitar signal? For instance, I use a compressor and run the output quite hotter than normal, this is further boosted by an overdrive pedal. How would overloading the input effect the V1 valves life? I normally run the first stage gains at about 1 o'clock with the inputs linked.

Thanks

The Aviator

[OldSchoolDave]

I must say the amp is now a completly different beast, and sounds incredible.

Great news. What your tech did would be considered standard maintenance for an amp that's nearly 40 years old. In fact, most get new filter caps and valves long before that.

Can this first input valve by easily damaged by overloading the input with pedals that boost the guitar signal? For instance, I use a compressor and run the output quite hotter than normal, this is further boosted by an overdrive pedal. How would overloading the input effect the V1 valves life?

Mark Huss is probably best equipped to answer that from a technical perspective.

My sense is that it's nothing to worry about. What would you rather have; a V1 valve that lasted "forever" or the great tone you get when you push it with pedals? For me, it's an easy decision .

Dave