I use the Epson Glossy Paper, works great.
To clean the cupper before, I use Sigolin (some metal polish brand).
Use the Iron at "Cotton" temp. Put 5 mm thick flat textile under the board for heating and apply the iron at least 1 minute.
After, just let it soak in hot water with some dish cleaner and wait, till the paper removes itselfs after soaking.
Then remove carefully the paper rests with a soft brush, still wet.
Before etching, correct the faulty parts with an simple permanent marker.
Franz
P.S.
Here the refined design, including a frontplate:
To clean the cupper before, I use Sigolin (some metal polish brand).
Use the Iron at "Cotton" temp. Put 5 mm thick flat textile under the board for heating and apply the iron at least 1 minute.
After, just let it soak in hot water with some dish cleaner and wait, till the paper removes itselfs after soaking.
Then remove carefully the paper rests with a soft brush, still wet.
Before etching, correct the faulty parts with an simple permanent marker.
Franz
P.S.
Here the refined design, including a frontplate:
An externally hosted image should be here but it was not working when we last tested it.
The project is going on. As it is so easy to post fotos in the forum "audiotreff", I just posted the latest fotos in this thread:
http://www.audiodiskussion.de/foren/selbstbau/msg.php?idx=43022
Franz
http://www.audiodiskussion.de/foren/selbstbau/msg.php?idx=43022
Franz
Thanks Greg!
It will be interesting to see, if the inspirations will lead to another very small tube buffered amps.
Just to illustrate the size
Franz
It will be interesting to see, if the inspirations will lead to another very small tube buffered amps.
An externally hosted image should be here but it was not working when we last tested it.
Just to illustrate the size
Franz
BTW: inspirations
I think, this IS one of the fascinating point with gainclones, despite of the audio qualities: the small and relatively cheap devices are a great base for creativity.
The original Gaincard is already a very creative design. It is, where the fascination started.
Many gainclones I have seen, are very very creative and some are professionaly designed, like the versions from Peter Daniel.
To tell the truth: my latest design was mostly inspired by the recently presented TATCA from Vikash. At this time, I had no plan to design another GC
Here the TATCA:
TATCA - Tiny And Transparent Chip Amp
Regards
Franz
I think, this IS one of the fascinating point with gainclones, despite of the audio qualities: the small and relatively cheap devices are a great base for creativity.
The original Gaincard is already a very creative design. It is, where the fascination started.
Many gainclones I have seen, are very very creative and some are professionaly designed, like the versions from Peter Daniel.
To tell the truth: my latest design was mostly inspired by the recently presented TATCA from Vikash. At this time, I had no plan to design another GC
Here the TATCA:
TATCA - Tiny And Transparent Chip Amp
Regards
Franz
Have a look at the GC on this link. It is the smallest GC I've seen (no valve though). I wonder if 2 could fit in the hole of the toriod.
http://www.headphoneamp.co.kr/bbs/zboard.php?id=diy_sijosae&no=203
http://www.headphoneamp.co.kr/bbs/zboard.php?id=diy_sijosae&no=203
grege said:Have a look at the GC on this link. It is the smallest GC I've seen (no valve though). I wonder if 2 could fit in the hole of the toriod.
http://www.headphoneamp.co.kr/bbs/zboard.php?id=diy_sijosae&no=203
When the GainCard took hold of the public imagination, most people, it seemed, were building GainClones as tiny as possible, and in unusual or creative enclosures. Now most of the boxes that we see that enclose GCs are fairly orthodox, and filled with more empty space than anything else.
It is refreshing to see Vikash's TATCA and Franz's design, and the GainTube in grege's link above. Thanks for the inspiration!
The amp is playing now for the first time: good as expected!
The power is exactly as expected in the beginning, clipping begins with 13.5VAC on 8 ohm, so 22W. My estimation 30W was wrong.
I think, the weekend is saved (for my childrens).
Franz
An externally hosted image should be here but it was not working when we last tested it.
The power is exactly as expected in the beginning, clipping begins with 13.5VAC on 8 ohm, so 22W. My estimation 30W was wrong.
I think, the weekend is saved (for my childrens).
Franz
Thank you Steen, for your compliment!
Look my youngest daughter: she is searching the amp:
She whishes an amp like this, really!
And, you may not believe it, today I visited the local high end dealer in Bern (High End Gallerie) and I got all this tubes (6922, 6DJ8, E88CC) for free (some of them brandnew, but oscillating in Vincent amps).
It is like christmas!
Franz
Look my youngest daughter: she is searching the amp:
An externally hosted image should be here but it was not working when we last tested it.
She whishes an amp like this, really!
And, you may not believe it, today I visited the local high end dealer in Bern (High End Gallerie) and I got all this tubes (6922, 6DJ8, E88CC) for free (some of them brandnew, but oscillating in Vincent amps).
An externally hosted image should be here but it was not working when we last tested it.
It is like christmas!
Franz
I tested all this tubes in the mini amp: no oscillation at all!
Of course, a cathode follower (gain < 1) does not tend to oscillate.
And if Vincent would have done a good job, they would have saved some money, as this tubes really are not subject of problematic oscillation tendency!
BUT: the 6922 are showing microphonics. The 6DJ6 and E88CC are all O.K.
Franz
Of course, a cathode follower (gain < 1) does not tend to oscillate.
And if Vincent would have done a good job, they would have saved some money, as this tubes really are not subject of problematic oscillation tendency!
BUT: the 6922 are showing microphonics. The 6DJ6 and E88CC are all O.K.
Franz
One week I had problems with the power on delay:
Because the amps box is so small, I must solve the delay within the PSU box.
I just inserted a relay for 250VAC/8A at the end of the +/- 25VDC rail, after 2x10000uF caps and before 4x1000uF caps in the amp.
The d@#°°@§§-delay circuit did not work well! Always after the first use, the contacts of the relay where hanging in working position.
First, I thougt, that I destroyed the relay when I caused a shortening while doing the first measurements.
So, bought a second relay. Same @#@@@§!!@ result.
Third relay.
Same
After that experience, I was completely dismotivated and asked a german valve forum, Jogis Röhrenbude.
Within a short time, I got aware, that I urged the relay to switch
MORE THAN 100 Amperes !!!
Completely out of range of this relay
Why so much? Because the already loaded 20000uF 50VDC will immediately load the empty 4000uF in the amp, causing such high currents and melting the contacts of the relay together!
Mea culpta...
BTW: in the new layout of the board, I included snubbers!
So, CarlosFM, in swiss german this is now a "snubberisierts" psu
I will compare soon the sound to my regulated but similar amp.
BTWBTW: I included a t-network with 47k input, to have the coupling cap physically small. So the t-net is now 18k/180R/18k and works very good.
Franz
Because the amps box is so small, I must solve the delay within the PSU box.
I just inserted a relay for 250VAC/8A at the end of the +/- 25VDC rail, after 2x10000uF caps and before 4x1000uF caps in the amp.
The d@#°°@§§-delay circuit did not work well! Always after the first use, the contacts of the relay where hanging in working position.
First, I thougt, that I destroyed the relay when I caused a shortening while doing the first measurements.
So, bought a second relay. Same @#@@@§!!@ result.
Third relay.
Same
After that experience, I was completely dismotivated and asked a german valve forum, Jogis Röhrenbude.
Within a short time, I got aware, that I urged the relay to switch
MORE THAN 100 Amperes !!!
Completely out of range of this relay
Why so much? Because the already loaded 20000uF 50VDC will immediately load the empty 4000uF in the amp, causing such high currents and melting the contacts of the relay together!
Mea culpta...
BTW: in the new layout of the board, I included snubbers!
So, CarlosFM, in swiss german this is now a "snubberisierts" psu
I will compare soon the sound to my regulated but similar amp.
BTWBTW: I included a t-network with 47k input, to have the coupling cap physically small. So the t-net is now 18k/180R/18k and works very good.
Franz
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