Hi,
Assuming you need more power than a single triode(d) amp (SE) can deliver I'd suggest to go for a P-P amp using a single pair of tubes.
Toplogy, penthode, triode, DH or IDH, NFB or no NFB is not something I'd decide on without knowing the more important speaker parameters.
Then of course there's also the issue of personal taste.
Either way, chances are that you'd obtain better results from keeping things as simple as need be, i.e. no PSE or PPP unless you really need to power....Upon which I'd suggest to buy or build some real speakers but I suppose you got the message.
Cheers,
Assuming you need more power than a single triode(d) amp (SE) can deliver I'd suggest to go for a P-P amp using a single pair of tubes.
Toplogy, penthode, triode, DH or IDH, NFB or no NFB is not something I'd decide on without knowing the more important speaker parameters.
Then of course there's also the issue of personal taste.
Either way, chances are that you'd obtain better results from keeping things as simple as need be, i.e. no PSE or PPP unless you really need to power....Upon which I'd suggest to buy or build some real speakers but I suppose you got the message.
Cheers,
Gday.
As you guys prolly. have figured out,
am basicly after making a very simple but good 30-40w pp,
(this would be a secondary project with a friend)
improved pre stage. (differential ?) and triode wire it.
(i guess one tube is better than another, regarding
regarding 30-40 pp in triode.)
Do you guys have a recomandation?
(I see there is at least two threads inn here, covering triode pp.
sounds interesting.)
I honestly don`t know, does it exist triodes for pp conection,
and in case, whats the bennefit over pentodes wired for
triode.
One more question:
What is the audible difference between 3. stage and 2. stage,
if there are.?
@fdegrove.
As of speakers, i have nothing much to go on.
They will certainly be easy drive/high sensetivety
and 4 ohm, (home buildt for sure)
@Brett.
The Hf/Mf are the main consearn. When it regards bass,
i gather most of the issues in Lf can be adjusted in the
loudspeaker prosses.
As you guys prolly. have figured out,
am basicly after making a very simple but good 30-40w pp,
(this would be a secondary project with a friend)
improved pre stage. (differential ?) and triode wire it.
(i guess one tube is better than another, regarding
regarding 30-40 pp in triode.)
Do you guys have a recomandation?
(I see there is at least two threads inn here, covering triode pp.
sounds interesting.)
I honestly don`t know, does it exist triodes for pp conection,
and in case, whats the bennefit over pentodes wired for
triode.
One more question:
What is the audible difference between 3. stage and 2. stage,
if there are.?
@fdegrove.
As of speakers, i have nothing much to go on.
They will certainly be easy drive/high sensetivety
and 4 ohm, (home buildt for sure)
@Brett.
The Hf/Mf are the main consearn. When it regards bass,
i gather most of the issues in Lf can be adjusted in the
loudspeaker prosses.
GeirW said:
Geir,
If you want 30-40W in triode (presume class A), then you'll either need to transmitter tubes or parallel outputs, say 845 or 813 (trioded) or PPP 300B's, KT88 (trioded) etc. Budget and working voltages are your limitations here.
The difference between two stage and 3 stage is another of those 'depends on design and implementation' questions. For example, most 300B designs use something like the cascaded 6SN7 to drive, whereas a pentode will do it just as easily, and to my ears MUCH better sounding than the 2x6SN7's. But for some, pentodes are against their religion.
If you have high eff speakers ie 95dB+ then likely you don't need 40W especially for MF and HF unless you have a HUGE room or are deaf. LF is what sucks up the power, but if you keep the xover low enough, say <60Hz, then you won't hear the vagaries of most SS amps if they're only run down there and reduces the requirements for the tube amp and opens up a lot more options.
It sounds like you're looking for a simple answer to a complex question, and you don't have all the variables, especially speakers in place yet. Speaks will have a big influence on the sound, so get them sounding right for you, then build the amp(s)
Gday.
@Brett.
30-40. in pentode conection, 15-20 in triode.
Maybe i should limit the wanted effect to 10-15w, coz. the
little thing i have right now, is dual mono el84 SE,
wich give mmm. 11-12w in pentode.
and that`s loud enough for me..
(ain`t exactly small listening room eighter.)
i was going for more juice for a bit more high-drive music,
like ex: NU-metal etc.-
@Brett.
bzzzz. perhaps i didn`t quite make that clear.
30-40. in pentode conection, 15-20 in triode.
Maybe i should limit the wanted effect to 10-15w, coz. the
little thing i have right now, is dual mono el84 SE,
wich give mmm. 11-12w in pentode.
and that`s loud enough for me..
(ain`t exactly small listening room eighter.)
i was going for more juice for a bit more high-drive music,
like ex: NU-metal etc.-
Hi,
Geir,
If that's the little Tandberg we talked about then you're looking at no more than 3-4W tops.
Should that not be loud enough then there's plenty of options but I would NOT run a penthode in SE mode as it will distort too much without NFB.
Applying feedback would reduce distortion and eat the magic
in the process.
No problem, you can run a bigger penthode such as the EL34 in pseudo-triode mode or choose from one of the more popular triodes.
Keep in mind that doubling the output power won't give the impression of twice as much acoustical power though.
Cheers,
Geir,
If that's the little Tandberg we talked about then you're looking at no more than 3-4W tops.
Should that not be loud enough then there's plenty of options but I would NOT run a penthode in SE mode as it will distort too much without NFB.
Applying feedback would reduce distortion and eat the magic
in the process.No problem, you can run a bigger penthode such as the EL34 in pseudo-triode mode or choose from one of the more popular triodes.
Keep in mind that doubling the output power won't give the impression of twice as much acoustical power though.
Cheers,
Gday.
No. it`s not that one, it`s another one .
Infact, this modell never got as long as production line
EDDA radiofabrikk, modell "TOR".
(not a radio, pure amp. stereo, tone controlls and gain,
3. line.)
I copied the amp. from a former co-worker,
god knows where he got it.
It`s Mullard`s 84, and if i got this right, they are rated to 5.7w
in SE pentode. (1.5 as triode)
Am still quite new to tubes, so maybe i read the datasheets
wrong.
No. it`s not that one, it`s another one .
Infact, this modell never got as long as production line
EDDA radiofabrikk, modell "TOR".
(not a radio, pure amp. stereo, tone controlls and gain,
3. line.)
I copied the amp. from a former co-worker,
god knows where he got it.
It`s Mullard`s 84, and if i got this right, they are rated to 5.7w
in SE pentode. (1.5 as triode)
Am still quite new to tubes, so maybe i read the datasheets
wrong.
GeirW said:
Design with a KT88 for that sort of power in PP class A triode/tetrode, and if you're careful with your choice of operating parameters, and add the neccessary filament supplies, you could substitute 300B's later of that's your cup of tea. KT88 tet mode will give quite a high output Z and will ideally need to use a different turns ratio on the OPT or feedback. One operating mode will be compromised.
If you're just going into clipping with the EL84 in pentode, then a PP KT88(T) will give a noticable improvement in sonics and headroom, but...
Frank is correct; somewhere around 10x the power is required to get an apparent doubling of volume with the same speakers.fdegrove said:
Makes an OK geetar amp though......fdegrove said:
Gday.
Hmmm. seems like there is a thing or two, i have totally
overlooked.
For this particular project i think it`s "safe" with 2x9w.
(the main aspect of this project, is to keep it simple & cheap,
with as good quality as possible within this range.
not to high voltage eighter.)
For one odd reason, i haven`t keept focus on those nummbers.
Hmmm. seems like there is a thing or two, i have totally
overlooked.
For this particular project i think it`s "safe" with 2x9w.
(the main aspect of this project, is to keep it simple & cheap,
with as good quality as possible within this range.
not to high voltage eighter.)
I think i know what you mean Brett.
I don`t like distortion at all,
For one odd reason, i haven`t keept focus on those nummbers.
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