Help! Considering building a tube amp

[Bando]

I have recently made a TDA7360 chip amp and for what it is ( car stereo ) it is a decent chip. I learned a lot from this chip since it is a very simple circuit and how things should and shouldn’t be grounded.



My friend though has just finished a decware SE84C with the metronome speakers. The sound stage was very nice and the very musical. I just really liked it.



For me tube amps are impractical, because I have a small child and another one on the way. I am not to keen ( nor is my wife ) on 330V+ in my living room. That’s the only room I have for listening.



Is there a chip amp that sounds really good. I don’t want a high power amp. Say 5 to 15 watts max, I have seen the overture series being mentioned quite often. The LM1886 in a mono block design seems nice but I want nice warm sound. I personally havent heard any overture chip.


What I listen to:
Jazz
Camber, Baroque, Classical guitar, not much but some romantic to post romantic era.



What the Speakers are:

My daughter has damaged my Fe83eN's and I am looking at another driver with at least 96 db sensitivity.



I have a outboard 24v ( +, -, ground ) power supply, if I could use that it would be great.


Thank you for your thoughts,

James

[djoffe]

As long as you don't push them past their limits, the LM3886's sound fine. Of course, that could be said of many amps. It would deliver more power than you're looking for, but that's not a bad thing.

There are a number of people (Ebay, etc). who make circuit boards for the standard configurations...you could pair it up with your +/- 24 volt supply, and would have a good solution for not much money.

I make a complete kit, the GT-101...everything is in there...as such, it costs more, but it would go together much more quickly...that could either be a good thing, or a bad thing, depending upon your objectives....

Akitika GT-101

[johnr66]

Tube amps are safe as long as the device is constructed properly to confine the HV within the chassis. Some tube designs are said to produce harmonics that are "pleasing to the ear". Chip amps use global negative feedback and fast components (internally) to keep harmonics minimal (THD). The recording, source media, speakers and listening room color the sound far more than any properly functioning amplifier.

Is your 24v supply +12,-12 or +24,-24 (48v). What is it's current capability? For the watts you need, the LM1875 or TDA2050 are super simple and sound fantastic. It depends on you PS you want to use.

[cotdt]

High voltage is safe if it is within the chassis. Besides, a 12V power supply like in a computer can kill you already. There are just so many other safety factors when dealing with power supplies.

[Fenris]

Bando,

I built a relatively simple EL84 amp that uses an outboard +24v power supply. All it would need is a wire or mesh cage over the tube area to keep curious finger out. Any properly designed amplifier should prevent users from putting fingers/appendages/etc into the working parts.

Just what the world needs - another EL84 amp

[Bando]

Originally Posted by johnr66

Tube amps are safe as long as the device is constructed properly to confine the HV within the chassis. Some tube designs are said to produce harmonics that are "pleasing to the ear". Chip amps use global negative feedback and fast components (internally) to keep harmonics minimal (THD). The recording, source media, speakers and listening room color the sound far more than any properly functioning amplifier.

No arguement bad input, you get a bad sound no matter how good your amp is. Though the tube sounds really nice.

Is your 24v supply +12,-12 or +24,-24 (48v). What is it's current capability? For the watts you need, the LM1875 or TDA2050 are super simple and sound fantastic. It depends on you PS you want to use.

I have two transformers I can put on this PSU
1. EI style +12, -12 VA unknown, I think larger since it powered a dukane PA system
2. Tordial style +6, -6 54VA

Originally Posted by cotdt

High voltage is safe if it is within the chassis. Besides, a 12V power supply like in a computer can kill you already. There are just so many other safety factors when dealing with power supplies.

your right I just have a healthy fear of electricity, just like being up high, the more the easier it is to hurt.

Originally Posted by djoffe

As long as you don't push them past their limits, the LM3886's sound fine. Of course, that could be said of many amps. It would deliver more power than you're looking for, but that's not a bad thing.

There are a number of people (Ebay, etc). who make circuit boards for the standard configurations...you could pair it up with your +/- 24 volt supply, and would have a good solution for not much money.

I make a complete kit, the GT-101...everything is in there...as such, it costs more, but it would go together much more quickly...that could either be a good thing, or a bad thing, depending upon your objectives....

Akitika GT-101

I do like the GT-101, the idea of a kit is quite appealing.

Originally Posted by Fenris

Bando,

I built a relatively simple EL84 amp that uses an outboard +24v power supply. All it would need is a wire or mesh cage over the tube area to keep curious finger out. Any properly designed amplifier should prevent users from putting fingers/appendages/etc into the working parts.

Just what the world needs - another EL84 amp

I am not a big fun of hybrid systems but if it sounds great why not.


I have heard that TDA and LM series chip sound different, is this true? I like the TDA2050 but its seems like 25watts is a lot. Tons of head room but I find 1 or 2 watts plenty loud enough with good drivers.

Will post soon with schematic of my PSU and I would like to have it critiqued. Is it better to start a new thread in power supplies or better to keep to this thread, for looking at the PSU?

[counter culture]

The Tripath TA2024 chip is often said to have a tube-like sound.

You can get a complete amplifier + a power supply for ~U$26 here:- 2 x 15W Class D Audio Amplifier Combo Kit w 12V 50W Power Supply TA2024 | eBay.

It runs off 12V, so despite what cotdt says, it is unlikely to kill or even hurt a baby. I've never heard of anybody being able to feel such a low voltage unless applied to the tongue.

There's a thread on the forum detailing modifications, but it may be that the manufacturers (Sure) have already taken these aboard. If I recall correctly, all that was required was to remove 2 caps from mine. I'm listening to the TV through it at the moment. It sounds just the same as the original Sonic Impact as far as I can tell.

You can read a review of the Sonic Impact here:- T-Amp - Class T integrated amplifier - [English]

It works best with an efficient full-range speaker like a Lowther or an Audio Nirvana.

[cotdt]

I will have to completely disagree with you here, counterculture. The T-amps do not sound anything alike to tube amps! If you want to see what 12V can do, why don't you try it with a 12V battery? It is very dangerous not "it is unlikely to hurt a baby." I got shocked pretty bad once.

The human cells operate in the 100mV range, so even low voltage is dangerous. It can stop a heart.

[KMossman]

Originally Posted by cotdt

The human cells operate in the 100mV range, so even low voltage is dangerous. It can stop a heart.

So he should have an amp with a V++ of < 100mV ?

I have to stop here........he says biting his tongue hARD.

[cotdt]

Well, he can bite into a 12V battery if he thinks "it can't even harm a baby"!