Help choosing right integrated amplifier for Snell Type C/V

[hifiamps]

My CD player has a digital output, I wonder if I can use the Protodac instead of the internal DAC of the Philips CD player. If I got it right, a cd player essentially read bits, and using the digital output you can save some money if you already have a DAC.

The Q7 seems good but is expensive. I'm wondering if clock like Accusilicon AS318-B worth it, and it need to be soldered? And the RPI Zero W, so you have soldered, as there are not presoldered GPIO headers?

Why does it sound so good? I'm looking forward to hear mine

I'm happy to have found someone in this forum that use Protodac. I'd be curious to know the results of ASR test about it

I'm considering purchasing a tube amplifier, I wonder what the pairing with the Protodac would be like

@DanielT @Blumlein 88 These days I was always looking for amplifiers, and I came across these, talking to sellers and other people:

- Xindac xa 6200 (1000 bucks) NEW
- Musical fidelity M6i (1100 bucks) USED
- AMC XIA 150 (959bucks) NEW
- Nad c372 (500 bucks) USED
- Synthesis Roma 510 AC (1800 bucks) NEW
- Electrocompaniet ECI-1 (1000 bucks) USED

Which of these could worth the money?

The cost of a Raspberry Pi Zero W with header is very low. About $16 USD. Use CUERipper to rip CDs to a USB thumb drive. Play your CDs and have access to internet radio.

You certainly could get a DIR9001 SPDIF to I2S converter board as a bridge from the CD player to ProtoDAC for about the same money, but much less flexible.

By the way, my other handle is hifinet.

An amp recommendation? Icepower Class D. Which one depends on the speakers. Even a TPA3255 based amp might be adequate.

 

[DanielT]

I'm considering purchasing a tube amplifier, I wonder what the pairing with the Protodac would be like

@DanielT @Blumlein 88 These days I was always looking for amplifiers, and I came across these, talking to sellers and other people:

- Xindac xa 6200 (1000 bucks) NEW
- Musical fidelity M6i (1100 bucks) USED
- AMC XIA 150 (959bucks) NEW
- Nad c372 (500 bucks) USED
- Synthesis Roma 510 AC (1800 bucks) NEW
- Electrocompaniet ECI-1 (1000 bucks) USED

Which of these could worth the money?

Tube amplifiers are usually very expensive in relation to the performance and power you get for the money (compared to solid state). If you think it's worth seeing the tube shine, buy a tube amp. I think tube amps are too expensive just to see the tubes shine, but that's me. You might see it in a different way?

Tube amps can be so bad that they color the sound. Or those who like tubed amps would say that's exactly why they're good. With tube amps and those who like them, it's a bit like turning the world upside down, so to speak. Tube amps are not my thing so on those I can't give you any tips or advice other than avoid them.

I see tube amps more as a remnant from a bygone era. On the other hand, I understand those knowledgeable in electronics who have it as a hobby to DIY fix tube amps, or renovate old tube relics. But that is a completely different matter.

How expensive used amps seem to be in Italy! Here's a tip if you want to see what used HiFi is advertised for in different countries:

Hifi Shark - Used, Second Hand & Pre-Owned Hifi from 400+ Sources

Search and compare second hand Hifi equipment from 400+ sources world wide. Search by popular brands such as Accuphase, Hegel, Krell, Luxman, Mark Levinson and Sonus faber, and by categories like floorstanding speakers, integrated amplifiers, speaker systems, turntables and more.

www.hifishark.com

A used Nad c372 in good condition was sold in Sweden, on an auction site, a few weeks ago for 228 Euro (see attached picture).

If you are thinking of laying 1800 bucks on a new amp and you like vintage looks so buy a Leak stereo 230. It has enough power to power up your Snell Type C/V with ease.

Measures well:

Leak Stereo 230 integrated amplifier Measurements

Sidebar 3: Measurements I measured a different sample of the Leak Stereo 230, serial number LH000805CFD1195, than the one RS had auditioned. I performed the measurements using my Audio Precision SYS2722 system. I preconditioned the Stereo 230 by following the CEA's recommendation of running it...

www.stereophile.com

I think it's really pretty:

LEAK STEREO 230

Amplificatore Integrato

1.399,00€ – 1.599,00€

LEAK STEREO 230

Amplificatore Integrato

www.hifimilano.com

 

[Willem]

I think used amplifiers are a bad idea. Modern manufacturing technology has made new ones very cheap and reliable. A Yamaha AS701/801 will do everything you need for a modest outlay. However, since the room is the real issue in any system, I would primarily look for systems with some form of dsp room equalization. Within the given budget, and to avoid making things too complex, I would suggest a combination of the DSPeaker X2 DAC/preamp and a Hypex based power amplifier from Audiophonix. The DSPeaker X2 will bring additional benefits if and when you decide to add some subwoofers once you have a larger listening room.

 

[Blumlein 88]

My CD player has a digital output, I wonder if I can use the Protodac instead of the internal DAC of the Philips CD player. If I got it right, a cd player essentially read bits, and using the digital output you can save some money if you already have a DAC.

The Q7 seems good but is expensive. I'm wondering if clock like Accusilicon AS318-B worth it, and it need to be soldered? And the RPI Zero W, so you have soldered, as there are not presoldered GPIO headers?

Why does it sound so good? I'm looking forward to hear mine

I'm happy to have found someone in this forum that use Protodac. I'd be curious to know the results of ASR test about it

I'm considering purchasing a tube amplifier, I wonder what the pairing with the Protodac would be like

@DanielT @Blumlein 88 These days I was always looking for amplifiers, and I came across these, talking to sellers and other people:

- Xindac xa 6200 (1000 bucks) NEW
- Musical fidelity M6i (1100 bucks) USED
- AMC XIA 150 (959bucks) NEW
- Nad c372 (500 bucks) USED
- Synthesis Roma 510 AC (1800 bucks) NEW
- Electrocompaniet ECI-1 (1000 bucks) USED

Which of these could worth the money?

Some of these I know about, some I don't. Truth is most non-broken amps of adequate power will sound the same. So does it have features you like, do you think it is cool? I think I already posted I'd personally buy one of the Purifi based amps. I think I agreed with another poster on one near your budget that looked pretty nice and was available near you. The one that looks cool, I'd go with the EC-1. Bang for the buck is the NAD C372. Good amp, enough power, enough features and the cheapest while also not being as old as say the EC-1. Also, if you decide you didn't get quite what you wanted the first time, buying cheaper and re-selling means lower loss of money potentially. I've purchased most of my gear used. So I'm not afraid of that.

This is just down to a psychological problem.....how do you feel about it, and what will make you happy? No one else can answer that for you.

 

[DanielT]

I rarely or rather never hear any difference between well built amplifiers
(or even bog standard ditto). I doubt would even if I had super duper good SOTA speakers that I would do that. Maybe if I really trained my hearing to detect differences, but well maybe not even then.
Low powered amps that are driven into clipping are, on the other hand, super easy to hear, detect the distortion then. That sounds too damn bad.

Now I have plugged in a receiver I forgot I had. It has been in a closet for a number of years. Pioneer SX777. That receiver of 65 watts together with speakers of 90 dB sensitivity works fine. Also, my normal listening volume in the apartment rarely exceeds 65 dB so I don't need many watts. In any case. It works really well with such an inconspicuous unsexy receiver as the SX777 is.

An SX777 used today, maybe around 50 Euro.

 

[edoardoz]

Tube amplifiers are usually very expensive in relation to the performance and power you get for the money (compared to solid state). If you think it's worth seeing the tube shine, buy a tube amp. I think tube amps are too expensive just to see the tubes shine, but that's me. You might see it in a different way?

Tube amps can be so bad that they color the sound. Or those who like tubed amps would say that's exactly why they're good. With tube amps and those who like them, it's a bit like turning the world upside down, so to speak. Tube amps are not my thing so on those I can't give you any tips or advice other than avoid them.

I see tube amps more as a remnant from a bygone era. On the other hand, I understand those knowledgeable in electronics who have it as a hobby to DIY fix tube amps, or renovate old tube relics. But that is a completely different matter.

How expensive used amps seem to be in Italy!

For an aesthetic reason tube amplifiers are awesome, plus the best setup that I've heard was with Tektron amplifiers (made in Italy).
I've seen this Synthesis Roma (also manufactured in Italy) that is discounted (3000 to 1800) and I was wondering if this sounds like Tektron or something similar, because probably I love how they color the sound. And yes, they are funny.

But I want to take time to think, as in march there is Milan Hi-Fidelity (hifi exhibition) with a lot of famous and not so famous brands, and there are a lot of rooms with audio setup, you can listen to the music and ask questions to the saleperson, which in many cases are the same engineers who design the devices.

But, yes, used amps are expensive in Italy. Lol, this NAD with 250 euros was a big deal!

 

[edoardoz]

Some of these I know about, some I don't. Truth is most non-broken amps of adequate power will sound the same. So does it have features you like, do you think it is cool? I think I already posted I'd personally buy one of the Purifi based amps. I think I agreed with another poster on one near your budget that looked pretty nice and was available near you. The one that looks cool, I'd go with the EC-1. Bang for the buck is the NAD C372. Good amp, enough power, enough features and the cheapest while also not being as old as say the EC-1. Also, if you decide you didn't get quite what you wanted the first time, buying cheaper and re-selling means lower loss of money potentially. I've purchased most of my gear used. So I'm not afraid of that.

This is just down to a psychological problem.....how do you feel about it, and what will make you happy? No one else can answer that for you.

Yes, you got it, is probably also something that need to make you happy. I often choose more with my heart than with my head

 

[edoardoz]

Hello here I am back,

I have many things to tell you (@DanielT @Blumlein 88 @hifiamps et al).

I have the dac ready, I remind you that it is the Protodac project, with the two Vishay Z-Foil resistors.
To power the it I opted for the official Raspberry charger, as it is equipped with Power Delivery.

I did a lot of listening to my friend's home, where we compared:

- Protodac Without reclocker (mine)
- Protodac With Allo Kali reclocker (his)
- Allo Piano (delta-sigma) with reclocker

He made me do all blind tests, I immediately felt the difference between the r2r and the delta-sigma, and I slightly preferred the delta-sigma.
It must be said that the r2r were not very run in, I know that they need at least 100 hours of listening and that the resistors are heated up enough.

I brought 3 songs that I know very well, which in my opinion pose problems for hi-fi systems and are found in high resolution:

- A song by a 70s prog band, Area: Arbeit macht frei: here I focused on the drums and the voice
- A song by a Berlin DJ and producer of Dub Techno music, Mike Dehnert, who works mainly with analogue synthesizers: here I focused on the bass and treble
- Bach's Brandenburg Concerto No. 5 (the one with the harpsichord): here I focused on the harpsichord which is the most difficult because it often remains "behind", and on the separation of the instruments, of this expanded organic chamber music ensemble

The substantial difference, but I'm talking about nuances, barely perceptible, was that the R2R sounded more "analog", warmer and softer sounds on the bass, sharper on the highs, while the delta-sigma seemed more "familiar" to me, probably because being from the millennial generation I'm more used to sounds like that. So everything is more detailed, more separated, colder.

However, I heard (almost) no difference between the Protodac with and without the reclocker. It must be said that the reclocker was not in the 22/24 Mhz frequency (unavailable) but the 44/48 Mhz one.

On the DAC side, the 3 songs listened to could be listened to in full without any problem from all the configurations tested. The differences between one or the other did not affect the quality of listening, rather they gave different versions but all equally valid.

We also did numerous tests with different amplifiers and two types of speakers (one of the two are the little sisters of my Snells). The amplifiers were all Sansui, including the 517 (which is the one I preferred), however none went beyond 65w for 8 Ohm. It also made me listen to two home-built power amplifiers in pure class A of 10w each.

After all these listenings I came to the conclusion that the Watts do not affect the clarity, on the contrary, the 10w were the best sounding on the highs, but rather I perceived the difference on songs with a lot of bass or simultaneous sounds, therefore in the Techno song and in the classic one.
The bass doesn't have the same fullness with few Watts and the instrumental separation in some passages is more mixed.

The A class was really felt in the Hi-Hats of the Prog song and in the voice, and in the violins of the classical song. But on techno music you could hear the lack of current.

As I expected, the real difference was audible when changing speakers.

After all these considerations, let's get to the point. I have almost completed the system: while I was desperately looking for an amplifier among the offers, I found the Synthesis Roma 510 AC, an 80W integrated tube amplifier, which I had spoken about, from this old guy who was reselling it after just 1 hour of listening after it was given to him as a gift because it was "too heavy" (25 kilos!).

I took it home with 1300 euros and 2 years of warranty activated the day before.

Furthermore, the left Snell that I had been repairing for almost a year arrived, the woofers were fixed and the speaker coils were changed.

In short, I now have the full working sound system!

Let's now come to the considerations:

- It all sounds very good, I did the tests from the USB stick and using BubbleUpnP with Tidal.
- The bass is very full-bodied, I had the sound of the reverbs analyzed with RT graphs of the room by a acoustic panel company in the area, who recommended two bass traps in the back of the speakers, and two hybrid panels behind the listening point. I must say that they are necessary, they will arrive this week and I will tell you the result.

- The 3 songs I was talking about before can be heard very well, perhaps a little detail is missing from the highs which seem hidden by the lows, perhaps due to the reverb problem

Some people advised me to run everything in for a few hours of listening, especially for the KT88 tubes and the DAC.

They also told me to change the RCA source cables between the amp and the DAC. Which ones do you recommend?
And even changing the power cord of the amplifier, I noticed that the transformer makes a slight noise. What type of cable could I use?
For now the distance from the wall of the speakers is 35/40 cm, do you think this is ok?

 

[hifiamps]

If there is a buzzing from the transformer, try to tighten the bolts a bit. I can highly recommend Grover Huffman cables. The electrolytic caps on ProtoDAC take about 60 hours to burn in. Play Sub FM internet radio for a few days. Try different 5V power supplies with ProtoDAC. Power supplies can affect bass, dynamics and the size of the soundstage. Kali will sharpen the focus.

 

[DanielT]

Hello here I am back,

I have many things to tell you (@DanielT @Blumlein 88 @hifiamps et al).

I have the dac ready, I remind you that it is the Protodac project, with the two Vishay Z-Foil resistors.
To power the it I opted for the official Raspberry charger, as it is equipped with Power Delivery.

View attachment 351039
View attachment 351040
I did a lot of listening to my friend's home, where we compared:

- Protodac Without reclocker (mine)
- Protodac With Allo Kali reclocker (his)
- Allo Piano (delta-sigma) with reclocker

He made me do all blind tests, I immediately felt the difference between the r2r and the delta-sigma, and I slightly preferred the delta-sigma.
It must be said that the r2r were not very run in, I know that they need at least 100 hours of listening and that the resistors are heated up enough.

I brought 3 songs that I know very well, which in my opinion pose problems for hi-fi systems and are found in high resolution:

- A song by a 70s prog band, Area: Arbeit macht frei: here I focused on the drums and the voice
- A song by a Berlin DJ and producer of Dub Techno music, Mike Dehnert, who works mainly with analogue synthesizers: here I focused on the bass and treble
- Bach's Brandenburg Concerto No. 5 (the one with the harpsichord): here I focused on the harpsichord which is the most difficult because it often remains "behind", and on the separation of the instruments, of this expanded organic chamber music ensemble

The substantial difference, but I'm talking about nuances, barely perceptible, was that the R2R sounded more "analog", warmer and softer sounds on the bass, sharper on the highs, while the delta-sigma seemed more "familiar" to me, probably because being from the millennial generation I'm more used to sounds like that. So everything is more detailed, more separated, colder.

However, I heard (almost) no difference between the Protodac with and without the reclocker. It must be said that the reclocker was not in the 22/24 Mhz frequency (unavailable) but the 44/48 Mhz one.

On the DAC side, the 3 songs listened to could be listened to in full without any problem from all the configurations tested. The differences between one or the other did not affect the quality of listening, rather they gave different versions but all equally valid.

We also did numerous tests with different amplifiers and two types of speakers (one of the two are the little sisters of my Snells). The amplifiers were all Sansui, including the 517 (which is the one I preferred), however none went beyond 65w for 8 Ohm. It also made me listen to two home-built power amplifiers in pure class A of 10w each.

After all these listenings I came to the conclusion that the Watts do not affect the clarity, on the contrary, the 10w were the best sounding on the highs, but rather I perceived the difference on songs with a lot of bass or simultaneous sounds, therefore in the Techno song and in the classic one.
The bass doesn't have the same fullness with few Watts and the instrumental separation in some passages is more mixed.

The A class was really felt in the Hi-Hats of the Prog song and in the voice, and in the violins of the classical song. But on techno music you could hear the lack of current.

As I expected, the real difference was audible when changing speakers.

After all these considerations, let's get to the point. I have almost completed the system: while I was desperately looking for an amplifier among the offers, I found the Synthesis Roma 510 AC, an 80W integrated tube amplifier, which I had spoken about, from this old guy who was reselling it after just 1 hour of listening after it was given to him as a gift because it was "too heavy" (25 kilos!).

I took it home with 1300 euros and 2 years of warranty activated the day before.

Furthermore, the left Snell that I had been repairing for almost a year arrived, the woofers were fixed and the speaker coils were changed.

In short, I now have the full working sound system!

View attachment 351041

Let's now come to the considerations:

- It all sounds very good, I did the tests from the USB stick and using BubbleUpnP with Tidal.
- The bass is very full-bodied, I had the sound of the reverbs analyzed with RT graphs of the room by a acoustic panel company in the area, who recommended two bass traps in the back of the speakers, and two hybrid panels behind the listening point. I must say that they are necessary, they will arrive this week and I will tell you the result.

View attachment 351044

- The 3 songs I was talking about before can be heard very well, perhaps a little detail is missing from the highs which seem hidden by the lows, perhaps due to the reverb problem

Some people advised me to run everything in for a few hours of listening, especially for the KT88 tubes and the DAC.

They also told me to change the RCA source cables between the amp and the DAC. Which ones do you recommend?
And even changing the power cord of the amplifier, I noticed that the transformer makes a slight noise. What type of cable could I use?
For now the distance from the wall of the speakers is 35/40 cm, do you think this is ok?

Congratulations on your new solution/amp. You have really been tinkering and fixing,especially with the DAC.

Feel free to take a picture of your tube amp when it shines in the semi-darkness. It usually looks nice with tube amps then.

Now that you're working on the acoustics in your room. You haven't thought about having a large thick carpet in front of the speakers? It can improve the sound.
Maybe dampen the first side reflex, but that's a matter of taste. You can try yourself.

Here is a nice inspiring thread:

Wood acoustic diffusers have become a decorative item - loved the idea!

Hi As an acoustician I am tired to tell people not to think room treatment only as absorption. In most small rooms absorption often creates more issues than it solves. Diffusion is a better solution. However, all I hear: they are expensive, ugly and difficult to place in a room. I am hence...

audiosciencereview.com

 

[DanielT]

After all these listenings I came to the conclusion that the Watts do not affect the clarity, on the contrary, the 10w were the best sounding on the highs, but rather I perceived the difference on songs with a lot of bass or simultaneous sounds, therefore in the Techno song and in the classic one.
The bass doesn't have the same fullness with few Watts and the instrumental separation in some passages is more mixed.

Speaking of amp power. In my relatively small combined living room, listening room. With 90 dB sensitive speakers using 67 watts (I plug directly into the power amp part of my NAD receiver) together with fairly undynamic lodness war exposed music, at 72 dB volume I still have 20 dB to pick up. DAC Topping E30 is then at minus 20:



BUT then I've been listening to Chill with Satie . Music with many almost silent parts that can increase in strength. In any case, my HK 330C receiver was not enough (30 watts before clipping) with my 90 dB speakers. Okay, I played really loud then.

My power amp SELA which has 125 watts was required for that. And then there is still classical music with more dynamics than that Satie record.

 

[edoardoz]

BUT then I've been listening to Chill with Satie . Music with many almost silent parts that can increase in strength. In any case, my HK 330C receiver was not enough (30 watts before clipping) with my 90 dB speakers. Okay, I played really loud then.
View attachment 351240
My power amp SELA which has 125 watts was required for that. And then there is still classical music with more dynamics than that Satie record.

I'll do a test tonight with the track you mentioned. If I can, I'll also take a photo to show the glowing tubes

I don't have volume control from the DAC, the only way I have to control the volume is through Moode, which I always keep at 100%, and from the amplifier.

What kind of test could I do to see the system's limits? I think if I play louder than 70 dB, it might alert the administrator.

What are you using to measure the dbs?

When you talk about dynamic I immediately though about Stravinskij or Dvorak.

 

[edoardoz]

If there is a buzzing from the transformer, try to tighten the bolts a bit. I can highly recommend Grover Huffman cables. The electrolytic caps on ProtoDAC take about 60 hours to burn in. Play Sub FM internet radio for a few days. Try different 5V power supplies with ProtoDAC. Power supplies can affect bass, dynamics and the size of the soundstage. Kali will sharpen the focus.

For the transformer problem I called the Synthesis assitance, they tell me a little noise is normal. But I see some other people with that that say that in some cases they have the same problem but others don't. I was wondering if changing te power cable can help, and probably add a dc filter can also help and give me a better result in general, like this one:

Audiolab dc block

On the dac's side:

I can't find the Kali recloker, some advices me to use Digi2 Pro as reclocker because it has adequate quartz.

What is your configuration with resampler / player? I'm using Moode and Bubble, do you think is a good way to reproduce music without loosing quality?

 

[Count Arthur]

For the transformer problem I called the Synthesis assitance, they tell me a little noise is normal. But I see some other people with that that say that in some cases they have the same problem but others don't. I was wondering if changing te power cable can help, and probably add a dc filter can also help and give me a better result in general, like this one:

Audiolab dc block

On the dac's side:

I can't find the Kali recloker, some advices me to use Digi2 Pro as reclocker because it has adequate quartz.

What is your configuration with resampler / player? I'm using Moode and Bubble, do you think is a good way to reproduce music without loosing quality?

Changing power cables will do nothing.

However, a DC blocker can be effective if your transformer hum is caused by DC offset on your mains.

There is a thread here: https://www.audiosciencereview.com/...-dc-blocker-to-help-stop-transformer-hum.948/

One thing to note about the Audiolab unit is that it's only rated for 4 amps, which may not be enough for more powerful amps with larger transformers.

ATL sell some capable of 10A: https://www.atlhifi.com/product-category/toroidal-hum/

 

[DanielT]

What kind of test could I do to see the system's limits? I think if I play louder than 70 dB, it might alert the administrator.

What are you using to measure the dbs?

To test its limits, well if you don't do it via measuring then only the ears remain. That means you can then test at a really high volume. If it sounds sharp, muddy and so on, you have driven the amp into clipping, the speakers can also distort, but it is often not as annoying as amp clipping /distortion. Experiment with really dynamic music. This is mainly noticeable if you get tired of listening to the distorting sound. You don't want to listen to the high volume anymore. But with a solution that can play distortion-free at really high volume, you won't be exhausted by the same sound level.

How your solution handles your "pedal to the metal test" doesn't really matter much if you only listen to music at a normal/low listening volume, say around 65 dB. But okay, it's always fun to test the limits of your solution, car or whatever it is, even if normally rarely not push that hard.

Try it when the neighbors are not at home is my advice. What power can your speakers handle? Check it out first.

My dB measurement was done with a free dB meter app. The accuracy may not be top notch but it gives a good indication. With such an app, you can check what your normal listening volume is in dB. There are tons of such dB apps. This is what I'm using now:

Sound Meter - Apps on Google Play

Sound Meter - powerful in its simplicity and convenience of use.

play.google.com

I'll also take a photo to show the glowing tubes Nice.

 

[DanielT]

.. EI noticed that the transformer makes a slight noise.

Is the noise coming from the amp itself or are you hearing it in the speakers?

What does that noise sound like?

How close to the amp, speakers do you have to be to hear that noise?

 

[edoardoz]

Is the noise coming from the amp itself or are you hearing it in the speakers?

What does that noise sound like?

How close to the amp, speakers do you have to be to hear that noise?

The noise is coming from the amp itself, to be more specific from the power transformer.
It is audible from 2 meters, is in low freq. When the music is playing is not audible, but in silence moments it is. It is not very loud, but if it wasn't there it would be better.
It does not appear immediately when turned on, but after some minutes.

@Count Arthur how can you determine how much amps is needed? You think Audiolab is not enough?


When I listened to it from the guy who sold it to me, even if I put my ear close I don't remember hearing any sound. He used a Yamamura cable and Yamamura power strip.

 

[Count Arthur]

The noise is coming from the amp itself, to be more specific from the power transformer.
It is audible from 2 meters, is in low freq. When the music is playing is not audible, but in silence moments it is. It is not very loud, but if it wasn't there it would be better.
It does not appear immediately when turned on, but after some minutes.

View attachment 351519
View attachment 351520

@Count Arthur how can you determine how much amps is needed? You think Audiolab is not enough?


When I listened to it from the guy who sold it to me, even if I put my ear close I don't remember hearing any sound. He used a Yamamura cable and Yamamura power strip.

What is the mains voltage where you live?

300W max power consumption at 230v is ~1.3A - 1.6A
300W max power consumption at 110v is ~2.7A - 3.5A
It will vary a bit depending on the power factor: https://www.rapidtables.com/calc/electric/Watt_to_Amp_Calculator.html

Looking at the fuse will also give you an idea.

 

[edoardoz]

What is the mains voltage where you live?

300W max power consumption at 230v is ~1.3A - 1.6A
300W max power consumption at 110v is ~2.7A - 3.5A
It will vary a bit depending on the power factor: https://www.rapidtables.com/calc/electric/Watt_to_Amp_Calculator.html

Looking at the fuse will also give you an idea.

Here in Italy is 220V, like (I think) all other countries in Europe.
So 4A is enough?

hifinet tell me to try to tighten the bolts. I see some people solved this way, some dont.
Some solved with DC filter, but others says that DC filter on tube amp is not a great idea.
Synthesis replaced some amplifiers for this reason.

But I think the noise level is tolerable, I don't think to send my amp for assistance for this. Also because the hum will never be completely silent, especially in a tube.

 

[Count Arthur]

So 4A is enough?

Should be.