I think we have to agree that the shoddy is a logarithmic unit of measure, so there will always be space at the far end for more shoddiness. But agreed, very very high shoddy factor.The shoddiness is off the scale.
GM70 PP
#211 Re: GM70 PP
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#212 Re: GM70 PP
I agree with every thing Nick posted above.
You may give some consideration to caging those GM70 valves, especially if children come visiting.
You may give some consideration to caging those GM70 valves, especially if children come visiting.
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#213 Re: GM70 PP
Ha! Let'em burn! This is high art.
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.
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#214 Re: GM70 PP
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
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#215 Re: GM70 PP
Looking back at this post from 2022, and the following, I think the filament supplies are immediately beneath the top plate with the valves and OPT. The HT PS is the bottom layer. Did you have any issues with proximity of transformers and magnetic fields? I've had a few false starts with boxing up GM70 and this method makes a lot of sense to me.izzy wizzy wrote: ↑Thu Aug 18, 2022 6:11 am Some pics. Hasn't got clothes yet.
GM70top.jpg
GM70front.jpg
GM70side.jpg
Ply is all baltic birch coz had some lying around. 1000V rated 2mm plugs and sockets carry HTs from PSU to audio chassis. An IEC plug carries the mains from PSU to audio and plugs into a socket under the HT caps on the finals filament module.
Brass furniture castors on the front as they can be seen with regular seat castors at the back.
How are the threaded bars fixed to the top plate? Is there a captive nut glued in the underside of the plate? I'm not sure if that would be strong enough considering the boat anchor beneath - perhaps the top plate is a laminate of two with the nut captive between the two?
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#216 Re: GM70 PP
Hmmm, the photos didn't come through, maybe this link works
https://www.audio-talk.co.uk/phpBB3/vie ... 39#p198539
https://www.audio-talk.co.uk/phpBB3/vie ... 39#p198539
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#217 Re: GM70 PP
Thank you. Just got to do a top venner job like you on the speakers.
We had 4 little ones over at Xmas around 5yo. They all escaped alive and un-burnt. We use the Cambridge A1 in the slot under the top unit for everyday like TV. I was more concerned about the turntable and arm but we've had little kids around for decades and no one yet has done anything to harm the system
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#218 Re: GM70 PP
Had more issues with the SMPS filaments and noise. There is a very very small buzz but haven't tried to get rid of it yet. Need to be very close to the speaker to hear it and they're quite sensitive. Yours probably more so. There's no noise from the output stage when isolated from the front end. Yet to investigate where that's coming from. Could be mag fields into the interstage txs.simon wrote: ↑Wed Oct 30, 2024 1:39 pm
Looking back at this post from 2022, and the following, I think the filament supplies are immediately beneath the top plate with the valves and OPT. The HT PS is the bottom layer. Did you have any issues with proximity of transformers and magnetic fields? I've had a few false starts with boxing up GM70 and this method makes a lot of sense to me.
How are the threaded bars fixed to the top plate? Is there a captive nut glued in the underside of the plate? I'm not sure if that would be strong enough considering the boat anchor beneath - perhaps the top plate is a laminate of two with the nut captive between the two?
Was surprised there's so little noise as it is tightly packed. Tried to keep the noisy things away from the sensitive stuff. Got more noise from ungrounded transformers cases/frames etc. Once all grounded, like they probably would be on a metal chassis, did it get quiet. It was way too noisy as first go until I did this.
If you check the pics at the bottom of the page https://izzy-wizzy.com/?page_id=58, the various blocks are outlined.
The top just sits on the threaded rods in location holes. The sides and back are screwed on and hold it together. It forms a rigid block which is easy to roll around. You're not picking it up by yourself! I roll it to the workshop and lift the top off to work on it. Top has a cradle to sit on upside down. It's a bit wobbly without the sides and back but it's been like that for years no issue. The top never fell off when unsecured, even wheeling it around.
#219 Re: GM70 PP
Absolutely loving the matching cosmetics of all your equipment.
Congratulations, very, very nice work!
Always a good strategy.SWMBO has had a major input to the design of it all as that's more her field than mine.
Congratulations, very, very nice work!
"When we're about to do something stupid, we like to catalogue the full extent of our stupidity, for future reference." - Commander Susan Ivanova, Babylon 5
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#220 Re: GM70 PP
Thanks, got it.
Interesting about the IT and hum - you reminded me that when I played with 10Y IT 300B I had unacceptable hum. I can't remember now whether it was proximity to the HT tx or the OPT that caused it, but it needed to be about a meter away from whichever was causing it ISTR. Probably the HT tx. Maybe grounding the iron would have helped. Thomas Meyer uses this type of construction a lot, and fairly densely, so it's presumably just a matter of location and orientation. And lots of trial and error.
Interesting about the IT and hum - you reminded me that when I played with 10Y IT 300B I had unacceptable hum. I can't remember now whether it was proximity to the HT tx or the OPT that caused it, but it needed to be about a meter away from whichever was causing it ISTR. Probably the HT tx. Maybe grounding the iron would have helped. Thomas Meyer uses this type of construction a lot, and fairly densely, so it's presumably just a matter of location and orientation. And lots of trial and error.
#221 Re: GM70 PP
Is this a new level of shoddiness ?! I like it.
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#222 Re: GM70 PP
Yep. This is excellent. Perhaps we need a new scale... a deciVark (dV) maybe? Named after that paragon of beautiful hand-crafted making, Tatjana van Vark - the decibel is, after all, named after AG Bell.
So, one dV would be 1/10 as good as kit made by TvV which would perhaps be equivalent to "shoddy" and the base reference for logarithmic ratios...
Vivitur ingenio, caetera mortis erunt
#223 Re: GM70 PP
Yes, and ideally 1dV would represent the minimum change in appearance that can be detected by an (average) human eye.
Maybe also have dVi and dVr to distinguish between comparisons from an image or in real life.
Maybe also have dVi and dVr to distinguish between comparisons from an image or in real life.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#224 Re: GM70 PP
And to add to that, when I say "minimum change in appearance" I am not talking about a tell them apart comparison, but a change in the shoddyness between two things (or the same thing after a change).
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
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#225 Re: GM70 PP
I looked up Tatjana van Vark. Wow! Perfect ambassador for a measure of shoddy.
Thanks for all the lovely posts.
Thanks for all the lovely posts.