[bengoshi2000]

I've found that 12AX7's will amplify any defect in the circuit.  On my build the higher gain tube, the more pot noise I get (cheapo RatShack pot).  12AT7's strike a good balance on my build.  YMMV.
 
I'm gearing up to build another SSMH with the add-on of a start-up delay.  Thinking about upping the capacity of the output caps as well in hopes of squeezing a wee bit more bass out of the amp.
 
This amp building stuff is frighteningly addictive...

 

[the_equalizer]

Quote:

Thanks for the complete and detailed answers, The_Equalizer. I didn't mean to ask about the difference in tubes as a discussion to find the best options, but simply to know if the one I have is a compatible part I can build the amplifier around.
 
Good to know the 12AU7 variation circuit can work with the 12AX7 without modifications. I'll do as you recommend then : I'll build the circuit as it is and try it out with the 12AX7. I'll see then how things goes. I have the AKG Q701, so it might be that gain won't be a problem. 

 
In the spirit of the Starving Student, I'll try to build the amplifier using as many recycled parts as I can. So it might take a while to build it. I'm not in a hurry anyways. I'm thinking about building it inside an old car stereo.. might look nice. And I could probably recycle the knobs and pots.

Good luck with your build! Don't forget that if you get stuck, this thread is here to help.
 

 
Quote:

I've found that 12AX7's will amplify any defect in the circuit.  On my build the higher gain tube, the more pot noise I get (cheapo RatShack pot).  12AT7's strike a good balance on my build.  YMMV.
 
I'm gearing up to build another SSMH with the add-on of a start-up delay.  Thinking about upping the capacity of the output caps as well in hopes of squeezing a wee bit more bass out of the amp.
 
This amp building stuff is frighteningly addictive...

 
It most definitely is addictive! I'm really interested in that start-up delay. Please post here if you manage to get it working nicely.  Good luck!
 
cheers!

 

[Fred_fred2004]

I just spotted this delay circuit, while looking at that crystal cmoy
 
http://runawaybrainz.blogspot.co.uk/2011/11/audio-simple-555-headphone-delayed-on.html
 
it looks very simple and cheap, it could be adapted
 
 

 

[DudeMyCans]

Just pulled the trigger on some 19j6's and all the associated bits to build me a MSSH.  Can't wait....

 

[Oeufdepoire]

I've just retireved some IRF640, and I wonder if they would fit the circuit as some IRF510 (that I don't own)  would. I've just peered at both's characteristics, and nothing, in theory, prevents me from using the 640.
So, I'd like to know : are the IRF510 the only transistor fitting the circuit, or some IRF640 would comply too ?

 

[Athur126]

Hi was thinking of building it but idk wether I can get the 19j6 Tubes.. Is it possible to use and alternative set of tubes? If so what kind and do I have to do any modification?

 

[bengoshi2000]

Quote:

Just pulled the trigger on some 19j6's and all the associated bits to build me a MSSH.  Can't wait....

Where did you find the 19j6's?

 

[DudeMyCans]

Quote:

Where did you find the 19j6's?

Got them off eBay. Try searching for them. They still seem to come up occassionally.
 

 

[DudeMyCans]

Quote:

Hi was thinking of building it but idk wether I can get the 19j6 Tubes.. Is it possible to use and alternative set of tubes? If so what kind and do I have to do any modification?

When I was researching this, I found that there's a few people built them with 12AU7's which have the benefits of being readily available (you can buy then new from musical instrument shops) and cheap. The schematic is slightly different but all the information you'll ever need is in this thread.
 

 

[piratetrips]

Hey guys,
 
I'm building the starving student amp and am about to order some tubes. I was wondering, which models are your favorites out of the 12AU7, 12AX7, and 12AT7?
 
Out of those models, which are your favorite brands?
 
Thanks!

 

[DudeMyCans]

Well I now have everything I need to build an amp sat on the desk infront of me 

    ....except I can't find any tube sockets...

 

[DudeMyCans]

 
Quote:

Well I now have everything I need to build an amp sat on the desk infront of me 

    ....except I can't find any tube sockets...

 
Sorted.
 
I've ordered the sockets, so should be ready to start next weekend.

 

[bnk0430]

Found a couple of 19j6, I'm going to order the parts and attempt to build it next week.

 

[KimLaroux]

I'm trying to find capacitor on Digikey.ca. I'm either not doing it right, or they carry very little audio quality capacitors... I am very limited to the choices.
 
For the output capacitor, isn't 63 volts a bit overkill? I mean the mosfets barely have 35v of peak to peak voltage. Would 50v caps be acceptable? Would using 35v caps asking for troubles?
 
They don't stock Nichicon ES... Is Elna RFS a good replacement? They look like nice caps to me. And they stock all of the sizes and voltages. At this rate I'll be using them for everything.

 

[Avro_Arrow]

Electrolytic capacitors need some DC bias to sound good.
About 3/4 of their rated voltage is a good target.
That being said, they also have to survive any voltage that
may be thrown at them...in this case as much as 48 volts
or whatever your supply is capable of if it malfunctions.
50 volts would probably be fine, but 63 volts is not unreasonable.
 
You may be able to get away with 35 volt caps, but don't be surprised
if they have a shortened lifespan or just go POP one day if they
see a unusually large spike.
 
I use ELNA RFS (Silmac II) on the output of my Bravo amp.
Power supply is 24 volts and I use 25 volts caps with no problem
so far.
 
I use Nichicon VR for the power supply cap. Requirements for audio
signal caps and power supply caps are quite different...it would be
a mistake to use the same cap everywhere.