My new (made in Calcutta) Tube amplifier

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.
Sure. You're welcome :)
 
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


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

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
Yes, Samwha are pretty good VFM caps and reasonable for what they do. I would still recommend changing these to better caps even if these are in the power supply section. I am working on restoring a vintage Sansui AU-DX701 amplifier, which is a phenomenal piece of vintage gear. For experimentation, I had put Samwha as the power caps but the difference was quite huge, when I went from Samwha to other better brands. Cheers!!
 
Yes, Samwha are pretty good VFM caps and reasonable for what they do. I would still recommend changing these to better caps even if these are in the power supply section. I am working on restoring a vintage Sansui AU-DX701 amplifier, which is a phenomenal piece of vintage gear. For experimentation, I had put Samwha as the power caps but the difference was quite huge, when I went from Samwha to other better brands. Cheers!!
I agree that better cap will bring better result.
Also the customer must be agreeing to invest the extra dough for the added improvement in sound quality. Once the customer agrees, then there is no problem in upgrading the components.
From the seller's POV and for the time being, Samhwa remains as best trade off between price n quality.
 
I always leave it to the designer to decide what’s best. At the end of the day everything is voiced. So you need to believe in the designers voicing.
I have experienced by changing a cap or a tube or footer to something more expensive doesn’t necessarily translate into better sound. Most times it messes up the balance which the designer had taken great pains to get right.
 
Fully agree with @prem . I have time and again noticed with my 300B tube amp setup that only silver plated copper wire seem to work for my setup. Use anything else the sound gets messed up totally. That's one of the reason in my DIY tubeamp i have gone only by the recommendation of my designer and mentor and refrained from all other expensive stuff. For instance i have used two snubber capacitors from Arktronics which is $10/- each. Same is available with Wima for $60/- which is 6 times more expensive. But my mentor have found that in this setup the Arktronics sound better than Wima for 1/6th the price.
 
4 or 8 ohms switch

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

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

I agree that better cap will bring better result.
Also the customer must be agreeing to invest the extra dough for the added improvement in sound quality. Once the customer agrees, then there is no problem in upgrading the components.
From the seller's POV and for the time being, Samhwa remains as best trade off between price n quality.
Agreed sir!! Cheers

I always leave it to the designer to decide what’s best. At the end of the day everything is voiced. So you need to believe in the designers voicing.
I have experienced by changing a cap or a tube or footer to something more expensive doesn’t necessarily translate into better sound. Most times it messes up the balance which the designer had taken great pains to get right.
Prem: I agree that it is the unit as a whole which matters. I also understand that designers probably want to use certain parts which are optimum considering performance and price points. However, if they have a buy-in from the end customer to increase the budget a tad bit more, they won't mind using some upgraded parts. I don't intend to start any debates around this topic. Only since I had directly compared this particular capacitor with other ones available locally, I wanted to suggest the same to the user to seek some future benefits. And my suggestions dont at all suggest that more expensive parts are always better. Just to clarify.

Yes, Samwha are pretty good VFM caps and reasonable for what they do. I would still recommend changing these to better caps even if these are in the power supply section. I am working on restoring a vintage Sansui AU-DX701 amplifier, which is a phenomenal piece of vintage gear. For experimentation, I had put Samwha as the power caps but the difference was quite huge, when I went from Samwha to other better brands. Cheers!!
Minor correction, the Sansui Amp model is AU-X701
 
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Kartick, I completely understand from where you are coming. And at most times, the increase in cost is marginal unless you are going in for some exotic stuff.

In cases where I have purchased an amp from a boutique designer, they normally don’t entertain requests to change caps and resistors and connectors. And this has nothing to do with cost or anything. They strongly believe that the sound they want from their amp comes from the parts they use.
 
I won't want to divert the thread from it's original celebratory theme any further, but to wish once again @madman29 on his new purchase and many pleasurable music listening hours.
 
Kartick, I completely understand from where you are coming. And at most times, the increase in cost is marginal unless you are going in for some exotic stuff.

In cases where I have purchased an amp from a boutique designer, they normally don’t entertain requests to change caps and resistors and connectors. And this has nothing to do with cost or anything. They strongly believe that the sound they want from their amp comes from the parts they use.
In my last amplifier (pioneer SA9900) I changed the main 2 capacitors as they were old. The replacement cap were Nichicon gold.
Now after the replacement am I supposed to hear some difference in the sq or not?
Most will say yes. But I'll say if there was a difference it was very small. Nothing that I will hear in a blind test.
Same result after I replaced the power transistors. 2 of them were faulty. I changed all 8. The difference in sq was not more than 1%
Now my point is that if the changes in sound is not more than 1%, I mostly just let them be the way they were. Unless the change is necessary.

Any change in components that is listenable without me knowing the swap is worth it. This is absolutely my personal opinion.
 
The Pioneer SA 9900 is a good amp. It will be using quality parts. If the caps are not spoilt, I see no sense in changing them. Which is why you probably heard no real change in sound. IME, changing parts only in the signal side bring about some changes. This does not necessarily mean it’s better :)
 
IMO&E, amplifiers are mostly built by listening and less by measurements. All decent amplifiers will measure quite well, and especially the ICs & SS ones measure exceptionally well compared to its tube counterpart. What is important to notice, is if the amp plays music or audio. A good test will be to listen to an actual musical instrument like a violin, tabla or something similar and compare if the setup sounded close to that. If yes, then its good no matter what is inside the amplifier w.r.t. exotic / boutique parts. If it does not play music as its intended to be then something is a miss. Also familar vocals are good source for testing. I am lucky in that way as my wife is a very good carnatic music vocalist and i have recorded some of her rendering in digital format. It gives me a very good indication of what is a hit or a miss.
 
The Pioneer SA 9900 is a good amp. It will be using quality parts. If the caps are not spoilt, I see no sense in changing them. Which is why you probably heard no real change in sound. IME, changing parts only in the signal side bring about some changes. This does not necessarily mean it’s better :)
I changed the caps as the best repair person in Calcutta told me one of them were not in good shape. And when I went shopping for the cap I went for the best I could afford. It also had some glowing description of what it could do to the sound signal. But I failed to hear those. I consoled myself and thought maybe my speakers are not up to the mark.
I think Prem ji you are right, sometimes we expect too much from those components.
Though I will change those RCA 6L6GC tubes at some point and use GE or some other make. Only in the quest to make the sound better. But if I could hear them or not will be a different story:)
 
RCA is very good. Why would you want to change to GE. Both GE and RCA are US tubes. IME, if you want a change in sound you should go for either UK or German equivalents. UK tubes normally are lusher and fuller sounding. German tubes like Tekefunken are more about resolution and detail. This is not to say these tubes are superior. It’s just that you’ll get a different flavour. Between two US brands I am not very sure if there will be any major difference.
 
RCA is very good. Why would you want to change to GE. Both GE and RCA are US tubes. IME, if you want a change in sound you should go for either UK or German equivalents. UK tubes normally are lusher and fuller sounding. German tubes like Tekefunken are more about resolution and detail. This is not to say these tubes are superior. It’s just that you’ll get a different flavour. Between two US brands I am not very sure if there will be any major difference.
I need to read a lot before I go for tube shopping. At present my knowledge is nil and I'm learning a lot from other threads from this forum. Thanks a lot for your suggestions. It will be a good starting point when I start looking for tubes.
Though getting NOS tubes is tough as I have come to understand.
In your opinion what tube should I look for if my listing choice revolves around 70s and 80s rock and pop.
I really like to hear realistic hi-hat or cymbal crashes and not miss the kick drum too
 
RCA Blackplates are very good. GE will be a bit more linear but less rich. Best would be original KT 66 Genalex tubes from Britain. But check with designer if it’s a direct substitute or he needs to make any minor changes.

Is your amp auto bias? What is your source and speakers
 
RCA Blackplates are very good. GE will be a bit more linear but less rich. Best would be original KT 66 Genalex tubes from Britain. But check with designer if it’s a direct substitute or he needs to make any minor changes.

Is your amp auto bias? What is your source and speakers
Thanks for the suggestions Prem ji. I can't understand the question about auto bias but I'll try to find out.
Source is mostly Sony CDP557ESD and some time Technics SL1200 with Nagaoka 110 MM cart.
Speaker is DIY
 
Madman29, you have a very nice set up. And pl address me as Prem. No ji after the name :)
 
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.
Looking at the images posted, the driver tubes are on the front side and the RCA at the back side. The signal path is too long which has to cross power lines, OPTs, final tubes and then reach the driver grid. Why can't you cancel the RCA from behind and have it somewhere in between the driver tubes. This will help reduce noise and improve S/N ratio. My 2 cents.

In my DIY tube amp, I have kept the driver tube just behind the RCA for short signal path.
 
Madman29, you have a very nice set up. And pl address me as Prem. No ji after the name :)
Prem, Shantanu's (Madman29) diy speakers are one of a kind. It's a JBL/Altec clone with front loaded horn and 15inch mid-bass, crossed actively.
Drivers are FaitalPRO.
 
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