Hello,
I bought an Hiwatt STA 200 (4KT*88) SN 1925 from the ~71 according to mark date and serial website. I tried to look at schematics but didn't found ones that clearly show how the little preamp that's in it works. So have some little stupid questions.
There are two inputs. I don't think it's one for high impedance vs low impedance, but i don't get how they are wire (i didn't had the time to put the head out of the chassis yet). So any of you familiar with this ? Could i put my bass through one preamp (that say for clean sound) in one input, and another preamp with a fuzz pedal on the other one ?
About the valves/tubes in the preamp i think there are only V1 and V2 from the DR201. If i get it right V1 act like a little preamp for the signal and V2 is the phase inverter before going to the power section ?? Does that still works if i put a preamp before going in the slave unit ?
Thanks a lot and i hope my topic isn't off for this board.
Regards.
hiwatt STA preamp
Moderator: Mods
Re: hiwatt STA preamp
Good afternoon, Vulcain, and welcome to the forum...
Slave amps of that period were exactly what the name implies, subservient to a pre-mixed signal, at 'line' level, typically from a console (for PA...) or another instrument amp with a line out.
Normally there would be 2 jacks, wired in parallel, so that the same signal could be injected into the slave, and 'daisy-chained' to another slave stacked above or below. This enables a number of slaves to be fed from one source output. One may use both jacks at the same time as input, they are identical.
The signal level required for a slave is considerably higher than that for an instrument amp (which has built-in pre-amp and EQ stages...). An instrument plugged directly into a slave will be at best audible, but no more. A slave is designed to be the power section only; the pre-amp is necessary to get anything like decent sound. Some pedals may have enough output to drive a slave, but the ideal set-up would have a decent dedicated pre-amp, and use the slave simply for driving the speaker cabs.
The KT88 valves, with the Partridge trannies, are designed to have very little distortion, and masses of 'headroom'. It would be difficult to drive them into lead guitar-type overdrive, except at inordinately loud levels (crumbling concrete is to be feared; ear protection at Apollo lift-off levels...). If one is looking for the 'Live at Leeds' sound from such a rig, get something else. I use a 200w KT88 PA (DR203...) for bass, exactly for it's mega-clean at any level, headroom to the sky. 'Dirt' must come from pedals. These are not 'Jimmy Page' emulators.
Just my tuppence worth, subject to other contradictory opinions; hope this helps...
Slave amps of that period were exactly what the name implies, subservient to a pre-mixed signal, at 'line' level, typically from a console (for PA...) or another instrument amp with a line out.
Normally there would be 2 jacks, wired in parallel, so that the same signal could be injected into the slave, and 'daisy-chained' to another slave stacked above or below. This enables a number of slaves to be fed from one source output. One may use both jacks at the same time as input, they are identical.
The signal level required for a slave is considerably higher than that for an instrument amp (which has built-in pre-amp and EQ stages...). An instrument plugged directly into a slave will be at best audible, but no more. A slave is designed to be the power section only; the pre-amp is necessary to get anything like decent sound. Some pedals may have enough output to drive a slave, but the ideal set-up would have a decent dedicated pre-amp, and use the slave simply for driving the speaker cabs.
The KT88 valves, with the Partridge trannies, are designed to have very little distortion, and masses of 'headroom'. It would be difficult to drive them into lead guitar-type overdrive, except at inordinately loud levels (crumbling concrete is to be feared; ear protection at Apollo lift-off levels...). If one is looking for the 'Live at Leeds' sound from such a rig, get something else. I use a 200w KT88 PA (DR203...) for bass, exactly for it's mega-clean at any level, headroom to the sky. 'Dirt' must come from pedals. These are not 'Jimmy Page' emulators.
Just my tuppence worth, subject to other contradictory opinions; hope this helps...
Have a good day.
Dad3353 (Douglas...)
Dad3353 (Douglas...)
Re: hiwatt STA preamp
Hi,
Thanks for your answer Dad and for your introducing. I'm from France too BTW, i think we might have speak together on Basschat (DR203 in France aren't so common). Ok i got the concept about the two inputs, i didn't thought about daisy chaining several slaves amp now i got it ! Thanks a lot. I also got the fact about clean sound no distortion and lots of headroom. That's why i come to Hiwatt.
I do have a preamp pedal that have a line-level output that i plug straight in my slave input and that works really great. The only problem i got is that it doesn't works really well with my woolly mammoth clone. Goes into feedback easily and erase the fuzz sustain a lot. My setup is bass -> fuzz -> preamp pedal -> Hiwatt slave. But now this is a problem i have to solve with my gear set up and nothing related to the Hiwatt so i'll figure this on my own. Thanks much for your explanations.
About valves replacement to get the best of this amp, do you guys have recommendations ? Going to record in one month or so and would like to get the best of that amp even if i must buy some expensive valves too.
Glad to be in that community,
Regards.
Thanks for your answer Dad and for your introducing. I'm from France too BTW, i think we might have speak together on Basschat (DR203 in France aren't so common). Ok i got the concept about the two inputs, i didn't thought about daisy chaining several slaves amp now i got it ! Thanks a lot. I also got the fact about clean sound no distortion and lots of headroom. That's why i come to Hiwatt.
I do have a preamp pedal that have a line-level output that i plug straight in my slave input and that works really great. The only problem i got is that it doesn't works really well with my woolly mammoth clone. Goes into feedback easily and erase the fuzz sustain a lot. My setup is bass -> fuzz -> preamp pedal -> Hiwatt slave. But now this is a problem i have to solve with my gear set up and nothing related to the Hiwatt so i'll figure this on my own. Thanks much for your explanations.
About valves replacement to get the best of this amp, do you guys have recommendations ? Going to record in one month or so and would like to get the best of that amp even if i must buy some expensive valves too.
Glad to be in that community,
Regards.
Re: hiwatt STA preamp
Well, the *best* would be original GEC NOS KT88s, but these have become almost impossible to find. The "GEC in name only" tubes being sold today are not in the same league.
FWIW, I put a matched and burned in set of JJ KT88s in my Fender PS300, and it sounds great.
--mark
FWIW, I put a matched and burned in set of JJ KT88s in my Fender PS300, and it sounds great.
--mark
Re: hiwatt STA preamp
Hi mark,
Yes the vintage ones i can find would cost at least as much as the amp himself. And as you both said the JJ KT88 works fine so i won't go trendy and listen to my ear. The JJ Works Great, were properly biased by a tube tech expert, I'll stay stick with them.
Yes the vintage ones i can find would cost at least as much as the amp himself. And as you both said the JJ KT88 works fine so i won't go trendy and listen to my ear. The JJ Works Great, were properly biased by a tube tech expert, I'll stay stick with them.
Re: hiwatt STA preamp
Seems it's my lucky era with vintage hiwatt.
Just saw a local ads for a 69 hiwatt dr103 head just checked out, at a decent price.
Is it worth the money to use it as main bass amp with the STA 200 ?
Using the slave out would it bypass the dr103 power amp section ?
I don't think so looking at the schematics but i'm not sure.
I'm not looking to have the power to play in stadium but it's really a matter of sounding like a guitar and bass at the same time.
Will probably need two staks of cabs.
As we are going to record in studio in one month that could be a good opportunity to get it.
Just saw a local ads for a 69 hiwatt dr103 head just checked out, at a decent price.
Is it worth the money to use it as main bass amp with the STA 200 ?
Using the slave out would it bypass the dr103 power amp section ?
I don't think so looking at the schematics but i'm not sure.
I'm not looking to have the power to play in stadium but it's really a matter of sounding like a guitar and bass at the same time.
Will probably need two staks of cabs.
As we are going to record in studio in one month that could be a good opportunity to get it.
Re: hiwatt STA preamp
The Hiwatt preamp is wonderful for bass IMO, but if may be overkill o buy a 103 just forthe preamp -- unless it really is a killer price. 
--mark
--mark
Re: hiwatt STA preamp
Good afternoon, Vulcain...
For recording, bass or guitar, I would look no further than a DR103, given the choice.
All in all, if you have the opportunity to grab a DR103, don't hesitate. The slave would become a complement when playing (very...) large venues, or could be passed on to another player to be made good use of. It would be fun to couple them, and it's not harmful, but I don't see any real advantage. If you're going for an ultra 'clean' bass sound, you still need a pre-amp for the slave. A DR103 would not be my first choice in this role.
Hope this helps...
Any sound DR103 at a 'decent price' is to be snapped up, budget permitting...Vulcain wrote:Seems it's my lucky era with vintage hiwatt.
Just saw a local ads for a 69 hiwatt dr103 head just checked out, at a decent price...
In my opinion, no. A DR103 on it's own is a formidable guitar and/or bass amp and, unless you're specifically in need of the extra power of 200w, the slave will not add anything. For studio use, especially, I can think of no advantage whatever, and quite a few downsides.Vulcain wrote:...Is it worth the money to use it as main bass amp with the STA 200 ?...
This would be about the only real use of a slave, if one has a DR103 to hand...Vulcain wrote:...I'm not looking to have the power to play in stadium...
This is different, however. If, by 'guitar', you mean pre-amp overdrive and O/P valves bending, then a DR103 is perfect. Great for clean too, of course. If, for the bass, you want this same facility, then look no further, the DR103 will oblige. Loud, clean bass is the realm of the KT88's, however. One would not need the Hiwatt pre-amp for that. Any good pre-amp will do a great job; the KT88's will take that to massive volume before breaking up. Not the same requirements as for guitar.Vulcain wrote:...sounding like a guitar and bass at the same time...
For recording, bass or guitar, I would look no further than a DR103, given the choice.
The standard 4x12 (or two...) is fine for guitar, and has been used for bass. Not my optimum choice, though. Again, stage work and studio are perhaps different needs; for recording I would go for a 2x10 for bass; maybe a 4x10. The sound engineer may have his say in the choice; he may be mixing direct with mic's; I doubt that he'd recommend the same cab as for guitar (one never knows, though...).Vulcain wrote:Will probably need two staks of cabs...
All in all, if you have the opportunity to grab a DR103, don't hesitate. The slave would become a complement when playing (very...) large venues, or could be passed on to another player to be made good use of. It would be fun to couple them, and it's not harmful, but I don't see any real advantage. If you're going for an ultra 'clean' bass sound, you still need a pre-amp for the slave. A DR103 would not be my first choice in this role.
Hope this helps...
Have a good day.
Dad3353 (Douglas...)
Dad3353 (Douglas...)
Re: hiwatt STA preamp
Hey dudes,
Thanks much for your answers ! Yes i do agree mark, buying just the amp for the preamp would be overkill. And looking at the schematics on your website, it's not that hard to build one from scratch. I think i was a bit too excited to explain myself clearly.
Mark yeah i do agree that would be pretty overkill to use a DR103 from 69 just for his preamp. Dad thanks a lot for your detailed answer !
I play in a scene with bands having likes having 2 drummers, 3 guitarist and like 5 amps on stage. We are moving a part from the sludge/doom trendy movement. However we would like to have that huge rock loud sound. I know that might sound teenage or stupid. But in my band we just got one drum, one bass, one guitar. And sometimes i'd like to be able to have that clean bass growling low end sound mixed with an overdriven guitar sound. But just with bass. So i though i could use a preamp with the STA (KT88) for the clean sound and the DR103 for that overdriven guitar sound. And sometimes both overdriven using fuzz pedals.
The idea is to have three floor of sound.
1/ All Clean
2/ DR103 Overdriven and STA Clean
3/ DR103 Overdriven with a fuzz pedals or cranked preamp (but i don't see how i could do that as dr103 as only got one preamp channel) and the STA overdriven by a fuzz pedal.
Regards, and thanks again.
Thanks much for your answers ! Yes i do agree mark, buying just the amp for the preamp would be overkill. And looking at the schematics on your website, it's not that hard to build one from scratch. I think i was a bit too excited to explain myself clearly.
Mark yeah i do agree that would be pretty overkill to use a DR103 from 69 just for his preamp. Dad thanks a lot for your detailed answer !
I play in a scene with bands having likes having 2 drummers, 3 guitarist and like 5 amps on stage. We are moving a part from the sludge/doom trendy movement. However we would like to have that huge rock loud sound. I know that might sound teenage or stupid. But in my band we just got one drum, one bass, one guitar. And sometimes i'd like to be able to have that clean bass growling low end sound mixed with an overdriven guitar sound. But just with bass. So i though i could use a preamp with the STA (KT88) for the clean sound and the DR103 for that overdriven guitar sound. And sometimes both overdriven using fuzz pedals.
The idea is to have three floor of sound.
1/ All Clean
2/ DR103 Overdriven and STA Clean
3/ DR103 Overdriven with a fuzz pedals or cranked preamp (but i don't see how i could do that as dr103 as only got one preamp channel) and the STA overdriven by a fuzz pedal.
Regards, and thanks again.