New Amplifier Design - "Murder One" - Submini Pentode, Low Voltage

[frequencycentral]

which means .... well there would be a lot of work

could you pleas try

This is a DIY forum.

DIY = Do It Yourself

I get emails periodically: "Hey, I've seen your Murder One, can you redesign it for me so I can build it using #### tubes".......kinda wears a little thin.

[robot797]

well the problem is
i only use tubes that has a seperate kathode
so i dont know hot to do it with a heater kathode

[iccaros]

well the problem is
i only use tubes that has a seperate kathode
so i dont know hot to do it with a heater kathode

you would have to provide 1.2v between pin 2 and 4. This is your cathode and heater. 4 to ground 2 to + 1.2. you are now biased for 1.2v on your grid. get ride of all cathode bias resistors and bypass caps, I do not think there are any in this design, and test.. Bread board first..  you could use a 1N5347B to bring that down the 12v to 2v and do something..

Why did you buy a lot of tubes you had no ideal how to use or a design to test with? I don't have any so I can do no testing. Your biggest issues is getting 1.2v for the heater. As Ricks design is for one tube load at that voltage. You

http://tubedata.tubes.se/sheets/127/5/5676.pdf

[robot797]

i got them for free

[jbgron]

[robot797]

i have re counted them the 5676 i have 38 of them
so i am kindof not knowing what to do with them

and wow so easy to djust it for this tubes!

[TNblueshawk]

Might I suggest selling those tubes, taking the money and buying some that will work for this cirucuit.

The DIY community is a great community of helpful people, but asking someone to basically build part of a circuit for you because you have some free tubes is pushing the envelope. If it was me, and for the sake of discussion here, had I wanted to ask this, I would have offered a bunch of those tubes as a gesture of reciprocation for someone to spend this kind of time or something.

But hey, that is just me 



With respect to the build and for what it is worth, the TC1044 sounds better to my ears in this. Could be my mind telling me it should so it does, but I guess perception can become reality. My signal keeps going out though and then comes right back. And I thought I had experienced all symptoms of screw ups. But alas, this is one I have not so I have to figure that one out.

[Perrow]

i have re counted them the 5676 i have 38 of them
so i am kindof not knowing what to do with them

and wow so easy to djust it for this tubes!

Send five to FC, wait a while and he'll post a layout

[robot797]

give me the adress
i will send 8 of them

[robot797]

well i did a DIY
i have a 1M to ground as a bias
and used my 5676 tubes

and also i used the output transformer i asked about

here it is

[iccaros]

sounds good..

[robot797]

it lacks a little base
but a good box shall fix that

now to get a battery that fits the box i have made (yes custom box for amp and speaker)

[frequencycentral]

Nice youtube. Well done for DIYing. 

[robot797]

thank you

[Joe Kramer]

Hey Friends,

Looks like a great project, love the simple elegance of the design.  I'd like to try building one of these to power a small speaker cabinet I've got.  After reading through most of the thread, it appears Version 7 is the most up-to-date revision of the circuit, but I don't see the schemo for it here.  May I ask that someone post or link to it here? 

Many Thanks!
Joe       

[iccaros]

I do not believe anything has changed since this page http://www.diystompboxes.com/smfforum/index.php?topic=73222.260

[Joe Kramer]

Thanks Steve.  Version 6 looks good, but I still have a few question regarding Version 7, which has a layout but not a schemo:

This is the layout I've been using for a while, verified. Version 7 - I'm such a tweaker. It dispenses with the bias switch and associated circuitry. It also includes (orange) pads and swiching diagram for adding a pre-out using the existing speaker out socket - it basically takes a tap from the preamp stage and also cuts power to the pentode when switche to pre-out mode. If you dont want the pre-out switch you'll need to jumper the orange pads together.

BTW, it's easy to build teh Modder's Delight without the bias switch, just a matter of not using a few components and wiring it slightly differently.

My question is, what are the changes in the "few components and wiring" regarding the bias switching for Version 7?  Since I intend to do my own perfboard layout, a complete schemo of V7 would save me from having to reverse engineer the stripboard layout.

Thanks,
Joe

[TNblueshawk]

Hey Friends,

Looks like a great project, love the simple elegance of the design.  I'd like to try building one of these to power a small speaker cabinet I've got.  After reading through most of the thread, it appears Version 7 is the most up-to-date revision of the circuit, but I don't see the schemo for it here.  May I ask that someone post or link to it here? 

Many Thanks!
Joe       

Joe, here is a thread you might find useful.

http://circuitworkshop.com/forum/index.php?topic=1046.0

[Joe Kramer]

Excellent--thanks Blueshawk!  I'll study a bit, and then probably come back with a few questions. . . .

Thanks again,
Joe 

[c3tester]

TNBluesHawk:

I've been off the grid for a while, but I received a PWB from Rick a while ago and I've finally started the Murder One build.  Thanks for all the previous tips on assembly of the board ...made it go smooth and quick.  I saw you wired an on/off switch to your Murder One.  I don't have that on Rick's schematics anywhere, did you have to put any drop-down resistor in series with the led?  How did you wire that circuit?  Thanks.