Beginner tube amp for 89dB speakers

[gaszto]

Well its hard to say because your budget is sort of hard to figure out.

Do you have 500 USD to spend or 500 Euro? I am going to assume you mean euro.

The cheapest transformers you can buy are probably going to be the lundahls. The average cost of a cheaper lundahl transformer is about 150 euro. So your two output transformers plus your power transformer will put you at 450 euros. That leaves you with no money for a filter choke, and it leaves you with hardly any money for tubes, tube sockets, resistors, and caps.

You might be better off buying an old vintage tube amp and refurbishing it.

In this case it looks like I have to increase the budget. I want to have fun, and want learn 🙂

 

[cbueche]

Well its hard to say because your budget is sort of hard to figure out.

Do you have 500 USD to spend or 500 Euro? I am going to assume you mean euro.

The cheapest transformers you can buy are probably going to be the lundahls.

I have to disagree, in Europe, Toroidy is cheaper. I'm not pretending they are the same level, better or worse, but definitely cheaper.

I would go for a Tubelab SSE, or a Millet Engineer Amp. Have done both and they are largely enough powerful IMHO. For a first build with PCB, almost nothing can go wrong and there are large communities around these amps to assist if something goes wrong anyway.

 

[VictoriaGuy]

Millet Engineer Amp

For me, building projects with 'common' tubes that will be available in the future makes more sense. The tubes are a fraction of the total cost of an amplifier.
I don't think Compactron tubes are still made??

BTW, I have the parts (board and tubes) here for two 'Engineer' amps, but haven't built it yet...too many projects!! 🙂😱

 

[cbueche]

For me, building projects with 'common' tubes that will be available in the future makes more sense. The tubes are a fraction of the total cost of an amplifier.
I don't think Compactron tubes are still made??

Correct, but when they cost 7-8$ a piece, you can buy some spares.
I have built two engineer amps, one with Edcor, one still in the "casing phase", with Toroidy. Great sound.
Another suggestion is this 6336 SET.

 

[gaszto]

There are other options:
IWISTAO Tube Amplifier Transformer Kit for 6P3P EL34 Tube Amp Including 1pc 160W Power & 2pcs Output Transformers HIFI Audio-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group

Thanks, the price looks good, but I'm bit worried about the quality. I check the price of Toroidy, or Lundahl (funny because currently I'm living in Sweden, and I will consider 🙂

I have to disagree, in Europe, Toroidy is cheaper. I'm not pretending they are the same level, better or worse, but definitely cheaper.

I would go for a Tubelab SSE, or a Millet Engineer Amp. Have done both and they are largely enough powerful IMHO. For a first build with PCB, almost nothing can go wrong and there are large communities around these amps to assist if something goes wrong anyway.

Thanks, Tubelab SSE looks very promising with a detailed building instruction.

 

[cbueche]

Thanks, Tubelab SSE looks very promising with a detailed building instruction.

yes, the SSE is a good amp, and if built with quality components, sound is great. I have 3 in the queue. One with large Electra-Print OPTs (got them cheaper but new), one with Ogonowski OPTs (didn't try them yet but the build is very serious quality) and a cheaper one with small Edcors, used for first tests before hooking 300€++ worth of iron to a new built amp. The ultimate OPTs in Europe would probably be these, at least for their look.

 

[VictoriaGuy]

because currently I'm living in Sweden, and I will consider 🙂

Putting your location in your Profile here at diyaudio will help!

Lundahl quality is very good by reputation - but you will need transformer covers if the transformers are above the chassis - the Lundahl transformers are very ugly and dangerous without covers. So add those to your budget. The Lundahl covers are $50+ each (and still ugly) in the US, so Chinese 'box' covers may be cheaper and better-looking?

 

[gaszto]

Putting your location in your Profile here at diyaudio will help!

🙂 I moved only a few month ago

but you will need transformer covers if the transformers are above the chassis - the Lundahl transformers are very ugly and dangerous without covers.

I will design a cover, I'm a mechanical engineer 😉

🙂 I moved only a few month ago


I will design a cover, I'm a mechanical engineer 😉

Nice with a swedish neighbor. Do you have means to lasercut stuff ?
Where are you located in sweden ?

Nice with a swedish neighbor. Do you have means to lasercut stuff ?

Yes, for example from some nice polished, or brushed stainless steel sheet. There are a lots of possibilities 🙂

Where are you located in sweden ?

I'm living in Örebro

 

[VictoriaGuy]

Do you have means to lasercut stuff ?

Yes, for example from some nice polished, or brushed stainless steel sheet. There are a lots of possibilities 🙂

Nice!
Laser or waterjet is the right tool for cutting those IEC power jack holes!
Or cutting stainless at all....(I hate that stuff!)
🙂

 

[gaszto]

I checked the spec's for the speakers and found them to be incomplete. 🙁 Nothing was provided about the impedance curve. If those speakers have dips in the curve, especially in the power hungry bass region, the sensitivity has to be derated. Dips down to 4 Ω require derating to 86 dB.

Thanks to DöG forum Audiodiyers forum, I got the impedance curve of my speaker. And It's right, 8Ω nominal impedance in the reality 4Ω with 3.2Ω minimum.