I finally finished my amp. Based on the Glasshouse 300BSE ....
Stunning build!
I keep zooming in on the photos to try to work out how you managed not to have any screws showing on the top. Is the top plate a sandwich with the screws countersunk under the beautifully elegant top plate?
I'll have to investigate your laser cutter. I'm now persona non grata with the local one I've been using after they messed up the last job on expensive imported panels. I insisted on a refund and they won't talk to me any more.
I keep zooming in on the photos to try to work out how you managed not to have any screws showing on the top. Is the top plate a sandwich with the screws countersunk under the beautifully elegant top plate?
The black plate with all the boards is sandwiched to the bottom of the top plate. Everything is fastened with treaded standoffs that are welded into the bottom of the top plate.
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Yes, everything is 3mm aluminium. Front is 10mm.
The whole reason I went with China is cost. Most local companies didn't want to do single pieces or charged a fortune for them.
Frontpanel express does really nice work but they couldn't anodise the panels after milling.
In the end, all panels combined, with shipping, the Chinese were something like 150€ cheaper then Frontpanel express.
It did take more effort explaining everything, checking, rechecking, lots of emails etc.
The whole reason I went with China is cost. Most local companies didn't want to do single pieces or charged a fortune for them.
Frontpanel express does really nice work but they couldn't anodise the panels after milling.
In the end, all panels combined, with shipping, the Chinese were something like 150€ cheaper then Frontpanel express.
It did take more effort explaining everything, checking, rechecking, lots of emails etc.
Yes, everything is 3mm aluminium. Front is 10mm.
The whole reason I went with China is cost. Most local companies didn't want to do single pieces or charged a fortune for them.
Frontpanel express does really nice work but they couldn't anodise the panels after milling.
In the end, all panels combined, with shipping, the Chinese were something like 150€ cheaper then Frontpanel express.
It did take more effort explaining everything, checking, rechecking, lots of emails etc.
Jeeezzz, that IS something I have to consider when I want to fabric a front panel. I did make a design for it but I am still reluctant to let them
realizing it into practice my front panel due to their huge costs.
RapidDirect made al the alu panels. I have to add that I had some issues, probably due to communication/language, but they where very helpful and in the end it all turned out nicely.
It definitely is different than dealing with a "western" company.
Thank you.
But in the end they anodised the plate ??
They first machined the parts, and then anodised them. This way you don't have any raw/shiny aluminium edges. See the attached image.
CoolJazz, how did you fix those treaded standoffs to the top panel?
I'm not sure how that works, I think they are stamped in. Frontpanel express can do them too
http://www.frontpanelexpress.com/products#studs
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Whoa! That's cool!
Yes, EF94 works in triode mode. You can read about parallel feedback in this document, although it is in Russian. Its author is Oleg Chernyshev
Simple put, parallel feedback is applied in parallel with input signal (think of inverting amp using opamp, where one resistor goes from the source, another one goes from the output). It decreases input impedance. If the amp had infinite gain before the feedback applied, the resulting gain would be the ratio between values of the resistors.
Series feedback is applied in series with input (think of cathode resistor, or additional resistor connected to it from output), it increases input impedance.
In case of an ideal opamp with infinite voltage amplification factor would be the ratio between values of resistors +1
The black plate with all the boards is sandwiched to the bottom of the top plate. Everything is fastened with treaded standoffs that are welded into the bottom of the top plate.
This is really nice design work and build quality - really well done
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