that sounds awesomes, i hope you get it working then you will have that great satisfaction.
your drivers license?
enjoy your holiday!
I believe you, what I meant to say was that the tube wasn't conducting thus there was no voltage drop. BTW I did built the real Mctube (long time ago), it's a fine pre for electric guitar.
black wire went to ground and the negative wire from the speaker went to ground then i hooked the positive wire from the speaker to the orange one from the OT into a 4ohm small speaker and alternatively the orange 8ohm into a larger 8ohm speaker. the larger speaker gave more volume they are rated at 89dB. i dont know what the smaller ones are rated at.
so the mp3 wont give full power? is that a measure of voltage and current output from it? r=e/i or output impedance against the input impedance of the amp? i never understood this. low current gives high impedance and the two have to be matched or something.
i was thinking of using this amp for the mp3 player. hmm so that wont work that simply. i ordered an other set of transformers to make the amp stereo. i took everything apart and mounted it on a stainless steel spaghetti strainer which im going to bolt to a square piece of plywood covered with kitchen cupboard liner lol with a nice kitchen motife.
im on the look out for some high efficiency speakers of about 94dB or better
thanks for all the help
fun time
Huh? I only see an orange wire, that gives you 10k with an 4 Ohms speaker. I will use the yellow, 2.5K is good for that tube and it will give you more power. It will give you 5K with an 8 Ohms. Try it.
An mp3 player puts out less than 1 volt, not sure what the standard is but mine gives .7 . You need 1.1 volt to get maximum power. Anyway, your problem isn't the mp3 player but the speaker sensitivity, 89dB is too low.
No need to thank me, the movie I rented turned out to be a bore and I'm too stoned now to do what I should be doing. LOL.
Last edited:
I´ve built this amp previously , and can second the large voltage slack during start up even though I have stronger 2.4Amp transformers. It sounds great and if you want to spend the $, Hawthorne audio make a high efficiency open baffle speakers, that rock with this amp. I am using it with Tang Band W4 in TQWT cabinets. At 89dB/m its loud enough for for listening in my office.
Ha Ha, kind of... Le Bus drivers licence
An externally hosted image should be here but it was not working when we last tested it.
i meant to say the green wire for 4 ohms.
i will try that as soon as i get it reassembled again. i took it all apart and am now building it inside the spaghetti strainer. could you elaborate on " I will use the yellow, 2.5K is good for that tube and it will give you more power. It will give you 5K with an 8 Ohms. Try it."? how did you calculate this and what are the basic principles involved here, just to give me a vague idea
Tube plate resistance is 750 Ohms, you have to choose a load 3 times that. Higher loads will give you less distortion and less power. 2.5K for 4 ohms, if you connect an 8 Ohms speaker the reflected impedance will be 5K. You won't understand this yet, so I'm not even going to try.
"am now building it inside the spaghetti strainer"
Did you miss the new Hammond wood chassis?
"am now building it inside the spaghetti strainer"
Did you miss the new Hammond wood chassis?
Last edited:
sounds reasonable. so it has to do with plate resistance. is it like a voltage divider? where the varying voltage in the tube resistance is reflected in the load resistance?
wood hammond chassis? i need to look at that!!
i didnt know stainless steel was so hard to drill through! can i use the stainless chassis for grounding, is it conductive enough? im going to run all the ground connections to one point on a terminal strip anyway
Well, you need to understand tube curves, it takes time. So much info if you search for it in Google. Don't want to write more that is necessary here, I'm lazy. Keep in mind though that you don't have to understand everything to build a tube amp. Experiment with different loads, listen and decide.
The Hammond's wood chassis reference was a bit of a joke as it costs more than your amp (100$) but it sure looks nice. Stainless steel is the worst choice IMO, conductive it is but VERY hard to drill.
The Hammond's wood chassis reference was a bit of a joke as it costs more than your amp (100$) but it sure looks nice. Stainless steel is the worst choice IMO, conductive it is but VERY hard to drill.
i want to build the other channel to this little amp.
do i need to double the entire power supply with other transformers and capacitors etc or will one do for the filament and plate voltages?
i have ordered all the parts to build another one but now im thinking that i dont need to build an entirely duplicate powers supply. is this correct or are the transformers too low in amperage rating
thanks
do i need to double the entire power supply with other transformers and capacitors etc or will one do for the filament and plate voltages?
i have ordered all the parts to build another one but now im thinking that i dont need to build an entirely duplicate powers supply. is this correct or are the transformers too low in amperage rating
thanks
k. im building both blocks in one chassis
thanks
a question about my st70 and popping sounds from the speakers with certain input.
i was getting popping sounds from the speakers with the output from the sacd player into a volume pot and from there to the st70. but when i just plug in the mp3 player into the amp i dont get any popping from the speakers. do you know what is going on? i guess i should drill a hole in the st70 and put the volume control there though i dont want to. i was getting the same popping sounds when i had the tube preamp plugged in.
it was about 5 months ago that i started with preamp projects so i could listen to other than my mp3 player through it. today many hundreds of dollars later im still listening to the mp3 player. LOL!!!
Last edited:
this is the volume control i was using. i just did what i thought might be correct.
the cables are new, the problem is probably in my set up here.
now im thinking it's the sacd player. it's a refurbished model from sony i got off of ebay. one disc was popping but it was on the track when i backed it up.
bizarre
Attachments
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.