Newbie project advice

[BHolmes]

Hello to everyone!

I am looking into buildin a really nice amp (sound and cosmetics) . I was looking at getting a turntable and realised that I needed a decent sounding amp. I have a nice CD player. But fancy a new project.

(Just to fill you in *probably shoud have put this in the intros section sorry!* I am an eletronics engineer and enjoy tinkering with things. I spend a lot of time working of guitar effects pedals and listneing to music. I think that it is time to have a decent amp and set of speakers to fully appreciate music)

So my idea for a new project was to build and amp and make a set of speakers to suit the amp.
I have had a look around and think that the Gainclone is a reasonable idea. Although I am sceptical about an amp with and IC!) So is the a good amp to start with?

Also I will be taking the ip from my CD player, do I need two amps for one side? If I do I assume that I can couple the volume control for both onto on pot and have a master volume.Hello to everyone!

I am looking into buildin a really nice amp (sound and cosmetics) . I was looking at getting a turntable and realised that I needed a decent sounding amp. I have a nice CD player. But fancy a new project.

(Just to fill you in *probably shoud have put this in the intros section sorry!* I am an eletronics engineer and enjoy tinkering with things. I spend a lot of time working of guitar effects pedals and listneing to music. I think that it is time to have a decent amp and set of speakers to fully appreciate music)

So my idea for a new project was to build and amp and make a set of speakers to suit the amp.
I have had a look around and think that the Gainclone is a reasonable idea. Although I am sceptical about an amp with and IC!) So is the a good amp to start with?

Also I will be taking the ip from my CD player, do I need two amps for one side? If I do I assume that I can couple the volume control for both onto on pot and have a master volume.

I also fancy making some speakers but have no idea about this, any recomendations?

Sorry if this has been asked in the past, if it has can someone please post a link to a previous thread.

Thanks very much!

I also fancy making some speakers but have no idea about this, any recomendations?

Sorry if this has been asked in the past, if it has can someone please post a link to a previous thread.

Thanks very much!

[Nuuk]

I hope you don't mind if I only type my answer once"

You could do worse than start by reading the GC pages on Decibel Dungeon. Then:

1 Build a Gainclone - there is nothing wrong with it being a chip amp!

2 I suggest building one using an LM3875 or LM3886 chip.

3 Use the discrete regulated PSU described on Pedja Rogic's site (or an SMPS).

4 Build the GC pre-amp as described on my site.

5 Have a look at the IPL site and choose one of their excellent kit speakers.

[BHolmes]

Nuuk,

I looked at your site to begin with (very good btw)

Just to confirm I will need two GC for each channel if I am just doing a left and right speaker (correct me if I am wrong).

For the PSU I was thinking about using 78xx IC's or 317's. Any reason as to why to use discrete comps over ICs?

Also a friend at work has said that building your own amp is a nightmare due to motor boating oscillating at frequencies that you can't hear that blow speakers, etc.

Is this true of the GC as it seems pretty fool proof.

Finally I was just going to build the GC without the pre-amp. What is the point of the pre amp?

Is it easy to add in after I have the GC working?

Thanks!

[Nuuk]

I'm very busy at present and I think most of your questions have been answered here before.

You can make do with two channels of amplification, unless you want to bi-amp or go active with a two way system.

The discrete regulted PSU sounds better.

The GC's sound better with a buffer or preamp but you can add those later if you wish.

Stick to a tried and tested design, build it carefully, and you won't have any problems no matter what Jonah says!

[dsavitsk]

Originally posted by BHolmes
Just to confirm I will need two GC for each channel if I am just doing a left and right speaker (correct me if I am wrong).

You will need one chip per channel. Thus, for left and right, you will need a total of 2 chips.

Originally posted by BHolmes
For the PSU I was thinking about using 78xx IC's or 317's. Any reason as to why to use discrete comps over ICs?

The chip amps do not need a regulated supply, and these chips will likely be too limiting of current. If you want regulation (and I think you don't for a first project) use someting with a higher current rating.

Originally posted by BHolmes
Also a friend at work has said that building your own amp is a nightmare due to motor boating oscillating at frequencies that you can't hear that blow speakers, etc.

Is this true of the GC.

No.

Originally posted by BHolmes
Finally I was just going to build the GC without the pre-amp. What is the point of the pre amp?

It makes it sound better.

Originally posted by BHolmes
Is it easy to add in after I have the GC working?

Yes.

[BHolmes]

ok, I'm getting the idea.

Can I just use a single transformer for the supply just with a single tap i.e 3 wires rather than one with a double ie 6. Or do in need two transformers for each channel?

[dsavitsk]

In general, you will get better sound if you use a separate transformer for each side. However, so long as you give the chips sufficient current and voltage, you will get good sound. Thus, one transformer, with just about any secondary configuration, will work.

[carlmart]

Originally posted by BHolmes

Can I just use a single transformer for the supply just with a single tap i.e 3 wires rather than one with a double ie 6. Or do in need two transformers for each channel?

Yes, you can use three separate wires instead of six. But try to separate the three wires into four, two for each side, as Thorsten Loesch suggested long ago. Use then separate bridges and make your ground junction further ahead.

This will contribute to less noisy supplies.

If you have six separate secondaries, try to make four pairs from them, following the same reasoning.


Carlos

[velmeran42]

Won't he need a phono-stage for his turntable?

[BHolmes]

I think for the moment I will just take the output from my CD player. Then think about sorting out the turntable at a later date!

Cheers for all the help!