My new (made in Calcutta) Tube amplifier

[madman29]

Hello everyone,

Its been long that I started a new thread.

I'll try to give some details about my new tube amplifier. This is my first tube amplifier. Before this I had a Pioneer SA9900 integrated amplifier. It was a vintage model. And to me it was irreplaceable. Well what do I know. But as it was quiet old, replacement parts were getting hard to procure. So I started looking. Mostly for branded amplifiers. Requirement was a low to medium powered amplifier with wide frequency capability.

I was very happy after I listened to an Arcam amplifier (I guess it was A28). I was also getting a big discount on the MRP. I was also fond of the popular Marantz amps in the 6xxx series as some of my friends were using it and they sounded good. But those amplifiers offered me nothing new that my Pioneer couldn't do. So the search went on...

At this point one FM from this site suggested me to look at tube amplifiers. And to my surprise he also gave me a persons name living in Calcutta making tube amplifiers. He also offered me to introduce me to him. So one rainy afternoon in this pandemic off we went to meet a seventy year young person who's very passionate about what he does -- make amplifiers.

That evening we listened to two amplifiers. One of them using the EL84 tubes. (The specs of the other one I forgot) The speakers he was using was no too good. Still the amp somehow managed to shine and sound nice. And it was not the same 'nice' that my Pioneer used to sound like. The bug inside my head shuffled its legs. Partha babu (Partha Banerjee) the person we went to meet also offered me the unthinkable... He gave me the amplifier for a few weeks for listening. And after a few weeks, or was it more than a month, I placed an order for the amp with him which I received within 2 weeks.

Well it sounds like the end of the story. Not so. Nope

The day I went to take delivery of my new amplifier Partha babu was tinkering with another amplifier. As any one from this forum, I too wanted to listen to that other amp. The tubes it was using was 6L6GC and 6SN7. The speaker used for the demo were the same. Lo and behold -- this amp I was listening to was much different form the EL84 based amp. First thing that came to my notice was the sparkle at the top end of the sound. Now I must admit here that it was nothing better than the EL84 based amp, it only sounded different. And as my choice of music comprise mostly of 70s and 80s rock and pop, I instantly had an idea what this amplifier could do for that kind of music

I asked Partha babu (with a guilty smile on my face) can I take this amplifier. 'Well this is not quiet finished" was his answer. So it was a wait for another couple of weeks.

After a few weeks from that day I was the happy owner of my new tube amplifier (the 6L6 one) playing Foreigner, Toto, Traffic, Eagles, Dire Straits.....

Some details about the amplifier:

1. 6L6GC Pentode used as Triode
2. 6SN7 Double tioode valve used as SRPP circuit
3. Power : 6 watt x 2 (Class A)
4. Price : Rs.40,000

Well now some pics.
I will post a review on how it sounds in coming months.

 

[keith_correa]

Very nice!
What is the function of the 2 rotaries and 2 toggle switches?

 

[prem]

I think the amp has only one input. I am guessing one toggle switch is for power and one is for mute and the two rotaries are vol control for left and right channels.

 

[madman29]

Very nice!
What is the function of the 2 rotaries and 2 toggle switches?

Thanks for visiting the post.
The two knobs are for left and right volume.
The yellow switch is to power on the amp and heat the tubes
The black toggle switch makes the tube function.
I know the answer is somewhat crude in describing the function but that's what those toggle switches does

 

[bhaskarcan]

Prem is correct, The two knobs are left and right volume. The two toggle switches are both simplified power buttons. The first one powers up the heater. After 30/40 seconds, the 2nd switch is used to supply HT/B+. A delay start circuit is used normally, but this one is decided to be simpler.

 

[madman29]

I think the amp has only one input. I am guessing one toggle switch is for power and one is for mute and the two rotaries are vol control for left and right channels.

Yes only one input. But I change the source from another place

Prem is correct, The two knobs are left and right volume. The two toggle switches are both simplified power buttons. The first one powers up the heater. After 30/40 seconds, the 2nd switch is used to supply HT/B+. A delay start circuit is used normally, but this one is decided to be simpler.

Thanks dada for coming to my rescue. You will be able to describe the function of this amp much better.

 

[bhaskarcan]

The circuit used is from Mullard Tube Manual. The transformers are all hand wound. It's a rare art that is vanishing with every passing day. The core for the transformers are of the highest quality Japanese core. Most of the components, specially in the signal path, are imported ones.
Tubes are NOS RCA ones.
The amp sounds heavenly with high efficiency drivers. I have tried it with my Tannoy Speakers and the combo was fantastic.

 

[prem]

Thanks Bhaskarcan for the clarification. I would love to hear this amp sometime. A lot of thought seems to have gone behind it.

 

[bhaskarcan]

Thanks Bhaskarcan for the clarification. I would love to hear this amp sometime. A lot of thought seems to have gone behind it.

Yes Prem. The person making them has almost 60 years of experience behind him making tube products. Though he remained an amateur because of his job as an assistant commissioner rank holder of Calcutta police. Now retired, he has re-booted his hobby again. He has keen ears for music and understands sound well.
The whole amp, including the cabinet, is hand made by him, only except the wood works.
A very interesting person to have worthwhile conversations w.r.t. sound, tubes, transformers as well as his days in police department.

BTW, he also makes killer Phono and Pre as well. Our forum member Souravin is one the many satisfied users.

 

[prem]

Very interesting. Next time I am in Kolkatta, would love to meet him.

 

[bhaskarcan]

Very interesting. Next time I am in Kolkatta, would love to meet him.

Sure, will love to accompany you.....

 

[madman29]

At this point I must say that Bhaskar da is the FM who introduced me to Partha babu

 

[stevieboy]

Congratulations Madman!

That's a lovely looking amp, am sure the sound matches up! Enjoy the sound of your new love!

regards

 

[keith_correa]

What's this for?

 

[Hari Iyer]

Great looking amp and choice of tubes. Am curious about what is inside the hood. Can any images be shared of the inside?

 

[kartick]

Many congratulations on the build. Tubes provide an absolute different feel to music and the immense joy of fatigue free listening for hours together is like no other. Next time I am in Kolkata, I am definitely meeting you and Partha babu!!

On a side note, are those Samwha capacitors? I feel you could do much better by replacing those with good Panasonic/Elna/Nichicon caps. I used Samwha recently as a replacement cap (in the signal path) and it did not sound as good as any of these other brands I mentioned. Perhaps, you could look at changing these sometime later. For now what is important is to enjoy the blissful sound of your new amp. Wish you all the best.

 

[madman29]

What's this for?

View attachment 51200

4 or 8 ohms switch

Great looking amp and choice of tubes. Am curious about what is inside the hood. Can any images be shared of the inside?

Very sorry but I don't have any pics of the inside

Many congratulations on the build. Tubes provide an absolute different feel to music and the immense joy of fatigue free listening for hours together is like no other. Next time I am in Kolkata, I am definitely meeting you and Partha babu!!

On a side note, are those Samwha capacitors? I feel you could do much better by replacing those with good Panasonic/Elna/Nichicon caps. I used Samwha recently as a replacement cap (in the signal path) and it did not sound as good as any of these other brands I mentioned. Perhaps, you could look at changing these sometime later. For now what is important is to enjoy the blissful sound of your new amp. Wish you all the byes there

Yes there may be certain components that may be changed to better ones in the future

 

[raghupb]

Very interesting!!
I'm looking for a tube poweramp too. 20W-ish for 88dB speakers.
The preamp will be a Lyrita DHT preamp.
Any suggestions @MADMAN @bhaskarcan from the gentleman who made this amp.

Cheers,
Raghu

 

[bhaskarcan]

On a side note, are those Samwha capacitors? I feel you could do much better by replacing those with good Panasonic/Elna/Nichicon caps. I used Samwha recently as a replacement cap (in the signal path) and it did not sound as good as any of these other brands I mentioned. Perhaps, you could look at changing these sometime later. For now what is important is to enjoy the blissful sound of your new amp. Wish you all the best.

Samhwa Caps are used as Power supply filter bank caps and they are not on "Direct" signal path. Since these are high voltage caps, Samhwa gives the best value for money performance in that position, without discernable sound compromise. Pana/Elna/Nichicon filter bank caps would have been obviously nice, but would cause definite increase in price.
All the signal path caps are film caps(Wima/Panasonic/Rifa/Epcos). Don't exactly remember which combination is there in this set.

Regards

Very interesting!!
I'm looking for a tube poweramp too. 20W-ish for 88dB speakers.
The preamp will be a Lyrita DHT preamp.
Any suggestions @MADMAN @bhaskarcan from the gentleman who made this amp.

Cheers,
Raghu

Hi Raghu, Mr. Banerjee has his own Pre amplifier to go with his Power amps. OTOH, since the power amps' circuits are quite generic, but at the same time follow highly reputed and time tested designs from the golden era of valve tubes, they should perform reasonably well with any pre driving them.
IMHO, for the best system synergy, it's best to stick to same brand for a pre-power combo, in your case Lyrita.

Regards

 

[madman29]

Congratulations Madman!

That's a lovely looking amp, am sure the sound matches up! Enjoy the sound of your new love!

regards

Yes the sound is very enjoyable and the highs are really nice. Tube amps are supposed to be warm sounding was my notion. But the very thing I like about this amplifier is the top end.
Will post a detailed 'how it sounds' review soon.