Help! Considering building a tube amp

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
 
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

Member
2009-03-05 1:55 pm
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.
 
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



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.

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.

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.

http://www.diyaudio.com/forums/tubes-valves/213947-just-what-world-needs-another-el84-amp.html

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?
 
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

Member
2005-10-30 12:57 am
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.
 
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Ok guys, yes a battery can still be dangerous.

I just thought that with tubes being exposed, being very hot and having high voltage wasn't that great of an idea with small children around.

I have touched a car battery with both hands on the terminals and nothing has happened. From what I remember from school you cant even feel electricity until 40 or so volts.

I get it, no matter what is used you have to be careful. I just wanted something that sounds fanastic that can live in a room and not be brittle or overtly dangerous. Since my toddler loves throwing things and I am sure that kids will be kids even when there older I want something that can stand some abuse.

If I cannot have decent sound and an amp that is more rugged than I won't build an amp.
 

cotdt

Member
2005-10-30 12:57 am
Don't be discouraged. Any amplifier design can be built safely, be it SS or tubes. The tubes don't have to be exposed. It can be put on a PCB and everything will be inside the chassis. Tubes don't really get that hot. In the old days, people used candles and kerosene lamps and had 10 kids, and they somehow managed. So don't be discouraged.
 

johnr66

Member
2009-03-05 1:55 pm
Actually low voltage DC can injure you, not by shock, but by electrolysis damage to your cells. You have to be in contact for a while, but keep that in mind when working around it.

My only issue with tubes is that the cost of quality parts can get downright costly. Look at the output transformers. You need two for stereo. If you're starting out, IC amps are simple and cheap. Just be sure to get authentic parts.