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Messages - doug7410

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Amplifier Discussion / Re: Crate BS-160 fuse blows right away
« on: June 26, 2009, 10:30:57 AM »
I checked them all (4) and all read about the same. No drastic differences in resistance.

Amplifier Discussion / Re: Crate BS-160 fuse blows right away
« on: June 25, 2009, 12:17:56 PM »
Ahh Haa, I'll check that out as soon as I get home from work.

Amplifier Discussion / Re: Crate BS-160 fuse blows right away
« on: June 24, 2009, 01:28:20 AM »
I looked them over and don't see anything that looks shorted. How can I test if one of them is shorted?

Amplifier Discussion / Re: Crate BS-160 fuse blows right away
« on: June 21, 2009, 09:02:53 PM »
I don't know. How can I test it for this?

Amplifier Discussion / Crate BS-160 fuse blows right away
« on: June 21, 2009, 02:46:23 PM »
Hi, I just inherited a Crate BS-160 bass/keyboard amp. It does not power up, so I looked inside. It has one fuse and it was blown. It's 250V 5A. I replaced it and it blew again instantly. I did notice the amp says to use normal blow fuses and I ended up replacing it with a rapid blow type. Could this make any difference? Any idea where I should start?

Thanks :)

Amplifier Discussion / Re: 22 watt per channel stereo amp project
« on: June 04, 2009, 10:11:29 AM »
Microcontroller... ??? I'm gonna have to google them, because I know nothing about them. Sounds good though. I think I saw a kit at Radio Shack called "My first microcontroller. I also think I saw a litte microcontroller board there for $50. I hope I don't have to spend that much for my switching. I really wanted to keep the cost of this thing as low as possible.

Thanks for keeping the ideas comming :) 

Amplifier Discussion / Re: 22 watt per channel stereo amp project
« on: June 03, 2009, 06:06:59 PM »
Wow! That footswitch would be awesome. And the really amazing thing is that all you need is a regular 1/4" guitar cable to connect it. I think it must be some kind of digital controller telling the amp what to do. The reason I'm breaking the channels down into two's is, in my tiny brain it's the only way I can see how I can have 4 selectable channels. And it can only let one preamp run at a time. So you don't accidently have more that one on at once. I could wire it so all the preamps run in series, and just use dpdt's to activate or bypass, but then you might end up with more than one on at a time. The wiring I did in the diagram would only let one run at a time.

Any ideas how to give them each a seperate switch?

Amplifier Discussion / Re: 22 watt per channel stereo amp project
« on: June 02, 2009, 10:57:42 PM »
That does sound cool. But I have no idea how it would work :-\

Amplifier Discussion / Re: 22 watt per channel stereo amp project
« on: June 01, 2009, 10:50:21 AM »
I came up with a way to switch between 4 preamp channels with led status indicators. There will be 2 sets of 2 channels. The 2 sets will be switched between with a DPDT toggle. That switch will go to another DPDT switch to choose one of the channels in the set. I have the diagram in the link below switched to the Dr. Boogie channel.

Now I need to figure out how to ad a footswitch option to this. Any sugestions?

Amplifier Discussion / Re: 22 watt per channel stereo amp project
« on: May 31, 2009, 04:10:11 PM »
I decided on the 22 watt figure simply because I had a power adapter that put out 12V and 5 Amps. A local electronic store had the chip in stock so I decided to give it a try. It can get pretty loud with the LM386 pushing it. As for the stereo channel, I am going to use 2 LM386's.

I agree most of the fets circuits will distort, but when you push a LM386 with the Tillman pre amp, you gets lots of clean headroom. I think this is because the gain on the fet never changes. I've tried a couple other fet circuits (fetzer valve), and they all have at least a little distortion. This one just doesn't seem to have any.

I'm still just experimenting, and so far I've been way happier with this than anything else I found for a clean channel.

I have even juged this against my 100 watt Peavey XXL solid state head, and this clearly sounds better.

I am building a small amp and found that these two circuits combined make a really nice clean preamp.

Don Tillman pre amp -
into a LM386 amp I found here

leave out the gain cap in that second link to keep it clean. You can also try skipping the first circuit and see what you think. I know this works really good for the power amp I made, but I don't know for sure how it will sound with yours.

You can see the project I'm using it for in this thread

These are really easy to put together on a breadboard, so give it a try and see what you think.

Amplifier Discussion / Re: 22 watt per channel stereo amp project
« on: May 30, 2009, 06:30:07 PM »
Hi Phil,

Yes, I am breadboardig this. The experimental parts at least. I built the power amp section and the Dr. Boogie. On the breadboard is the Tillman, the Baxandall EQ, and The LM386 circuit. So far I've been able to get a really nice clean chanel with the Tillman in front. I'm going to test that with some stomp boxes in front to see what happens.

Don't worry about hurting my feelings. I'll be the first to admit I'm learning as I go. Please let me know if you see anything wrong with my ideas so far.

Amplifier Discussion / 22 watt per channel stereo amp project
« on: May 29, 2009, 11:13:56 AM »
Hi Everyone,

I have posted some threads about the SS amp I'm making and it's really starting to come together now (circuit wise). I wanted to post my progress on this in case anyone is interested, or if you have any comments, questions, or constructive criticism. Here is what I have so far.

The plan is to make a stereo multiple channel combo amp with the following features:

• mono and stereo inputs, the left jack will be mono, left and right are stereo
• Multiple channels - So far I know there will be a clean, and a Dr Boogie channel
• effects loop
• extention speaker cap out
• whatever I can think of next....

Power Amp - this is the power amp circuit I'm using
It's 22 watts per chanel. I made a PCB layout in Eagle cad and built it allready. It works!

Pre Amp - This is made out of several circuits combined
I'm using stomp box amp emulators to get the distortion channels. I'm using a Don Tillman pre amp circuit with an eq
for the "Clean" channel.

• Clean Chanel- Don Tillman pre amp -
   that goes into a Baxandall EQ -
   then it goes into a LM386 amp I found here
   I'm adding a gain pot between the cap and pin 1 of the chip.

• Metal Chanel - Dr. Boogie  -
   Then into a Tillman pre amp then into a LM386 amp with no cap between pin 1 & 8, so there won't be any additional gain boost.

As of now I have only tested with one side of the amp chip. I've tried out an 8" 25 watt/50 watt musical( I still don't know what that means)  4 ohm Jensen. I also ran it thrugh my Marshall 4X12 cab.

I havn't figred out the effects loop, or stereo parts yet. I think I'm only going to do stereo through the clean channel. I'll just double the clean preamp. All the other channels will just be mono.

I'm thinking about adding a Run Off Groove UNO and a Thor. I might be getting carried away.

I'll post some sound samples and pictures soon. Let me know any ideas you have and what you think.


The speaker/cab is my 15 watt vox combo. I just disconnected the speaker from the combo amp and put a 1/4" jack on it to connect to my diy amp. That buffer idea sounds really good. I didn't try piggy backing the two ROG circuits yet because I've only had them assembled on my bread board. First I did the tone mender. It really sounded pretty close to being good, but it was missing somthing.

Then I did the Prof. Tweed. It sounded good at one setting and with the neck pick up. But it wasn't consistet. Maybe I need to try a tonemender into a prof. tweed and a buffer at the end. What do you think?


I built this power amp circuit

I'm only using one chanel right now, so it's just a 22 watt mono amp. I'm using it with a guitar speaker (not HI FI).

So I tried putting a couple different preamps in front of it. Both from

Tone Mender -

Professor Tweed -

Both sound great into my regular amp, but they don't quite turn the 22 watt circuit I made into a real guitar amp. The make a huge improvement over the power amp alone though.

My question is, is there anything I should do to the power amp circuit to make it more like a guitar amp?

Does anyone have any sugestions for pre-amps or a combination of pre-amps?

My goal is to have a 2 chanel (clean & distortion) amp with master volume.

Thanks, Doug

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