the uber simple circuit, except the cathode lifted from ground, and connected though a 1.5 ohm derivation in the secondary
Attachments
Dear Mosquito, I wonder the speaker driver you use in the project, I build with this trade name Audifiel® when I was 13, in the year 71', You could remember me this times in my childhood. Tell us, how sound the 2,5SE with this OB and the venerable alnico ?
I feel deep that in this thread tastes are tastes. I say deep that anybody wouldn't qualify the aspect that anybody else got from colour combinations, forms and materials that the humble or magnificent finish of the member could show and teach to the rest of builders. IMHO, On step of criticize we should learn "the better" that is obtainable from the designs. This is the thread in which ordinary like me and you can show our works, and at least the minimum rather than criticize is that at least remain silent
Esteban, I picked the two Audifiel, and the four Baldwin ovals, in a garage sale from an old lady, she was clearing stuff of his recently passed away husband (a former radio/TV repairman). The result is a sort of giant "boombox" except the sound is not "boomy", but clear and detailed. Voices in the AM radio are amazingly real, and sound from digital sources comes out excellent, and very loud (you can see a DVD player on a slot in the front panel, and a FM-SD card + USB player module, in the other corner). Sadly, the Audifiel factory go in bankruptcy some months ago after 60 years of production, leaving us without the last surviving Argentine loudspeaker producer. There was a lot of "tube friendly" units in their catalog,.. snif !
I think that is a fantastic finding, valves, transformers, LEEA, UCOA how quantity of things and thinks I am remembering of our incredible country. There are a thread in an Argentinian post that they speak only about LEEA®, they produce speakers(altec lansing copies with excellent sound and spl) microphones, and vinyl magnetic cartridges, by hand. Federico Martinez de Hoz encourage to disappear this part of the glory that we had in those times with the sacrifice of our grand parents. Nowadays the actual paradigm is "Alpargatas Si, libros no" Who wanna try to get an Audifiel speaker?
Last edited:
Design is not art. There is a right and a wrong way to design something.
There are rules. My wife has two masters degrees in design. It is a serious profession.
I think people giving design advice are helping, the same as people giving circuit advice. We are all here to have our designs critiqued.
Hi all, I have made some circuitry update and take few measurements of my modified Per-JadisJA30 - now with better compensation of power supply noise (it is no anode voltage stabilisation there), it achieved better S/N ratio than -90dBfs @50Hz, and it kepps other noise floor basically bellow -110dBfs.
Photos, some schematics and measurements could be seen here:perys | perys - Jadis-JA-30_mk2012 ? rajce.net
Photos, some schematics and measurements could be seen here:perys | perys - Jadis-JA-30_mk2012 ? rajce.net
An externally hosted image should be here but it was not working when we last tested it.
Much like music.. And while there is no doubt music is art, there is definitely a wrong way to play it!!
well basically, the only times I have had my feelings hurt on the photos forum is when no one says anything at all. I've never seen mean criticism about peoples amps. It's generally polite advice, which someone always takes offense to! (and it's never the amp builder).
Everybody knows where is the stone into the shoes.
Colours and forms are subjective adjectives. I think seriously that every body could be perfectible and imitating another non objectives properties. If someone likes to use a Ferrari mustard colour this car gonna be the same but a man with protanopia or deuteranopia or with daltonism not will perceive the mustard colour but he gonna knows that is a Ferrari. Here, there are things that belong to the facts of members and many of them do the best and find the best for show to the rest. My wife also has a perfect sense of design and what mean this point of view?
Circuit design is an a different objective property and deserve a help or a critique.
Colours and forms are subjective adjectives. I think seriously that every body could be perfectible and imitating another non objectives properties. If someone likes to use a Ferrari mustard colour this car gonna be the same but a man with protanopia or deuteranopia or with daltonism not will perceive the mustard colour but he gonna knows that is a Ferrari. Here, there are things that belong to the facts of members and many of them do the best and find the best for show to the rest. My wife also has a perfect sense of design and what mean this point of view?
Circuit design is an a different objective property and deserve a help or a critique.
Last edited:
Hello Vincent,
Really breathtaking construction!
How long have you been working to achieve the results as photos show?
Can you supply us with some technical information about your GM-70 SE amplifier (bandwidth, global NFB, cathode caps, scope diagrams and so on...)?
Are you satisfy with Lundhal OPT sound?
Regards,
Jarek
PS. It's a clever idea to use separeted amp and PSU box as it's less harmful to your spine.
Really breathtaking construction!
How long have you been working to achieve the results as photos show?
Can you supply us with some technical information about your GM-70 SE amplifier (bandwidth, global NFB, cathode caps, scope diagrams and so on...)?
Are you satisfy with Lundhal OPT sound?
Regards,
Jarek
PS. It's a clever idea to use separeted amp and PSU box as it's less harmful to your spine.
Thank you Jarek! This one took me 3 months to design and build, but it's not my first one...
The upper -3dB point is at 31kHz, outputs 30W RMS, no NFB, no cathode caps (fixed bias).
The Lundahl LL1688 sounds very good, but the high frequency square waves on the scope show that it has some resonances. Because of this, I would probably choose another transformer for a new GM-70 project.
Regards,
Vince
6xx7 amp
My new pcb's arrived!!
The basic board is for a stereo 6EM7 amp including PS.
You can use a tube or diodes. The board is configurable too.
You can make a pre-amp with it as cascode with a 6SN7 or just 2 stage with 6EM7 if you need to drive something big. There is also a subwoofer output.
Small board. Lots of possibilities.
My new pcb's arrived!!
The basic board is for a stereo 6EM7 amp including PS.
You can use a tube or diodes. The board is configurable too.
You can make a pre-amp with it as cascode with a 6SN7 or just 2 stage with 6EM7 if you need to drive something big. There is also a subwoofer output.
Small board. Lots of possibilities.
Attachments
yes, I had made 3 seperate boards before, mono and the PS but that still had a "lot" of wiring. now I'm almost "wireless". I've made about 25 amps with the small boards, now I'm more free to configure them the way I want. I can drive a 300B or a KT88 or KT150 or even an RS607. Or just listen to almost 2W of pure single tube audio pleasure.