"it is just SO hard to get bad sound from EL84 PP amp"

[rick57]

Anyone agree/ disagree?? Or is the writer just biased?

Context: amazingly cheap made in China amps.

Cheers

 

[Gaucho]

Interesting...just yesterday I heard a really nice (and cheap) Italian amplifier with EL84s. I believe it was made by Synthesis.

 

[analog_sa]

It is just as hard or harder to get really good sound from EL84PP amp 🙂

 

[planet10]

Certainly PP is harder to get decent than SE, and you can screw up anything, so sure it is possible to get bad sound from an EL84 amp... get it right thou and it is soooo sweet.

dave

 

[Layberinthius]

This brings up an interesting thought that I need rectifying...

Could I run an EL84 in SE with a 10k ohm OPT with only a 3 WV power limit and still sound good?

 

[rick57]

I thought it was a (somewhat silly) blinkered statement, checking my judgement.

Thanks all kindly.

 

[planet10]

Could I run an EL84 in SE with a 10k ohm OPT with only a 3 WV power limit and still sound good?

I think it may well be less of an issue with power and more to do with the current the OPT will handle before staurating

I would say you can go ahead and try it... the bass will start to go away when overloaded. Triode strapped an EL84 is good for a couple watts max, that may help. Parafeed is also usually beneficail for that as well.

We are going to try some of the IXYS CCS chips with some EL84 SEs and see how that works out (so far parafeed duties have been done with the primamry of an idential OPT)

dave

 

[amperex]

'just so hard'

I disagree, as it is real easy to get crappy sound from any amplifier. If one likes warm tube sound, that is, full of fuzz & distortion, no problem.

Careful design using best tubes, coupling caps, a good power supply design, quality plate resistors in the preamp tube anode circuits plus quality audio transformers will make a transparent tube based amp that lets the music flow.

So far, nothing is better than the GE 6BQ5 grey oval plate in many different amps I and others own. That is a good starting point. Usually the Asian audio transformers are fairly well designed. So, with some part changes & tube rolling, a good amp can be had & EL84 based quality amps do have a nice tone.

 

[Giaime]

Hello! I too own an old stereo integrated EL84 amp made by an obscure italian brand (Perser), it's cathode biased... The construction seems to be good, it has 2 ECC83 for the phono/pre stages, a ECC82 with chromed-like plates for driver and 2 EL84 per channel. The rectifier is GZ34. Do you think it's worth the restoration or not? I mean, push pull EL84 are good for hi-end or only SE would do? I know that SE is mostly everytime better than PP, but specifically about EL84s?

 

[anatech]

Hi again Giaime,
Yup, go for it. I own good sounding tube amps and solid state amps. Different but both are very enjoyable.
-Chris

 

[Giaime]

Hello Chris! I find you almost anywhere... 😀

Yes! I will restore it and maybe will post photos! (if I can get a digital camera)

 

[planet10]

Re: 'just so hard'

nothing is better than the GE 6BQ5 grey oval plate

Got some pictures of those? Detailed enuff to ID a tube from its internal structure?

dave

 

[planet10]

Do you think it's worth the restoration or not? I mean, push pull EL84 are good for hi-end or only SE would do? I know that SE is mostly everytime better than PP, but specifically about EL84s?

Not necessarilly a restoration, but certainly use it as a donor to build a modern amp

This John Swensen differential EL84 looks VERY interesting.... Within its power rating i suspect it is a real giant killer.

There are a couple more threads than the one i pointed too, so you'll have to dig a bit to get it all...

dave

 

[anatech]

Hi Dave,
Since Giaime is just starting, restoration may be a good way to learn something before jumping in. He can recycle it later.
-Chris

 

[Giaime]

Hi Dave,
Since Giaime is just starting, restoration may be a good way to learn something before jumping in. He can recycle it later.
-Chris

Thank you Chris, that was what I intended.

(you are starting to protect my interests, and I'm starting to think toghether with you, that's the start of a great friendship 😀 )

 

[Gaucho]

Thank you Chris, that was what I intended.

(you are starting to protect my interests, and I'm starting to think toghether with you, that's the start of a great friendship 😀 )

It's good to have friends in your corner...especially if they are technicians.🙂

 

[Giaime]

...here where I live it's extremely hard to have a technician for friend...they all laught when you say "tube"...

 

[richwalters]

Hi there.......I've made several EL84 p-p trype amps....they sound better when used with parallel pairs of tubes.......this nicely lowers the load Z to create better bandwidth . On the whole I find the sound differences between different vintages far less dramatic when used in compound configurations. 3 parallel pairs of EL84 sound way better than the basic EL34 p-p. OMO

richj

 

[anatech]

Hi Giaime,
Nah, Dave was just making a good suggestion. I've got a Heathkit torn apart I was going to rebuild. It's been 10 yrs., should have simply rebuilt it.
There aren't many new true technicians out there. Part engineer and unwilling to let a repair get the better of them. There are many good enginers and technicians who live here it seems. Really helpful too.
-Chris

 

[Giaime]

Yes, you know, I'm on the "junky" side of diy, I like to reuse anything and buy nothing, I'm very poor 😀 .

With some old integrated amps I have now at home (see the thread on "SS amps") I will start soon to rebuilt it... you know, fuse holder (it was missing), IEC type mains plug, RCA connectors...