Doc modding Marantz imperial 7

A place for DIY project discussions.
User avatar
karatestu
Posts: 4787
Joined: Sun Jan 08, 2017 4:40 pm
Location: North Yorkshire
Has thanked: 1047 times
Been thanked: 616 times
Great Britain

Re: Doc modding Marantz imperial 7

Unread post by karatestu »

Done some more research on concrete - highly interesting stuff :obscene-hanged:

I am looking in to using crushed glass as a total sand substitute. It can give a marble effect when polished up and would save me having to apply a finish over the concrete. It's a recycled product as well :dance: But which colour of glass and should I mix colours? That's my next decision.

Mix will be cement, crushed glass and some flow enhancer so I can use less water (stronger) and increase the workability. Not sure on the exact ratios I will use yet. Using glass can make the concrete stronger apparently especially if the size of the particles is kept low (sand sized).

I know nothing of the acoustical changes (if any) of using glass rather than sand. :whistle:
These users thanked the author karatestu for the post:
CycleCoach (Wed Aug 11, 2021 8:39 am)
DIY inspired by Richard "The Doc" Dunn RIP

User avatar
karatestu
Posts: 4787
Joined: Sun Jan 08, 2017 4:40 pm
Location: North Yorkshire
Has thanked: 1047 times
Been thanked: 616 times
Great Britain

Re: Doc modding Marantz imperial 7

Unread post by karatestu »

Just when you thought (hoped) that this ridiculous thread had quietly fizzled out into an eternal state of nothingness it pops back up like a turd in the bath.

If anybody here thought that I actually knew what was going on then I hate to have to tell you that I haven't a fecking clue. Led by donjeys would be a good way to describe it :grin: Just like this ridiculous government- I feel as useless as the Rt Hon Gavin Williamson the education secretary. This endeavour will ultimately waste a lot of tax payers money and end up getting binned due to being unfit for purpose. There was a glimmer of hope but the prospect of actually pulling this one off is going to need metal tits and will probably be about as hard as trying to convince the climate change denying mormons that human activity really is to blame .

I am now completely convinced that this whole thread has been planted in my mind by Russian agents with the sole purpose of causing confusion in the multi billion pound UK subjective music appreciation industry. I now urgently need to purchase a microphone and software to measure the frequency response of these speakers. It's all very well and good rewriting the laws of physics but nobody is going to believe me without some lovely graphs showing frequency response, impedance, directivity, group delay and phase.

Live long and prosper.
These users thanked the author karatestu for the post:
CycleCoach (Sun Aug 29, 2021 11:02 am)
DIY inspired by Richard "The Doc" Dunn RIP

User avatar
CycleCoach
Posts: 416
Joined: Tue Nov 15, 2016 5:20 pm
Location: Kings Cliffe
Has thanked: 492 times
Been thanked: 86 times
EUROPEAN_UNION

Re: Doc modding Marantz imperial 7

Unread post by CycleCoach »

You certainly don't need to worry about your fibre intake if your turds float....
These users thanked the author CycleCoach for the post:
karatestu (Sun Aug 29, 2021 12:15 pm)
Current System: Linn LP12 Lingo Ekos Troika, NVA Phono 2, Cambridge Audio CXC thru Cheapo Chinese DAC & PS, NORD streamer, NVA P50sa, NVA A80 x2 (they're special ones.), NVA SSP Mk2, NVA LS6, NVA Cube1

Geoff.R.G
Posts: 1238
Joined: Thu Aug 11, 2016 2:46 pm
Location: Denham UK
Has thanked: 64 times
Been thanked: 248 times
Great Britain

Re: Doc modding Marantz imperial 7

Unread post by Geoff.R.G »

karatestu wrote: Sun Aug 29, 2021 9:54 am Just when you thought (hoped) that this ridiculous thread had quietly fizzled out into an eternal state of nothingness it pops back up like a turd in the bath.

If anybody here thought that I actually knew what was going on then I hate to have to tell you that I haven't a fecking clue. Led by donjeys would be a good way to describe it :grin: Just like this ridiculous government- I feel as useless as the Rt Hon Gavin Williamson the education secretary. This endeavour will ultimately waste a lot of tax payers money and end up getting binned due to being unfit for purpose. There was a glimmer of hope but the prospect of actually pulling this one off is going to need metal tits and will probably be about as hard as trying to convince the climate change denying mormons that human activity really is to blame .

I am now completely convinced that this whole thread has been planted in my mind by Russian agents with the sole purpose of causing confusion in the multi billion pound UK subjective music appreciation industry. I now urgently need to purchase a microphone and software to measure the frequency response of these speakers. It's all very well and good rewriting the laws of physics but nobody is going to believe me without some lovely graphs showing frequency response, impedance, directivity, group delay and phase.

Live long and prosper.
The moment you take measurements it ceases to be subjective and becomes objective. If you don’t know how to use the software the results won’t even be objective but speculative. Save your money and use the two highly sensitive instruments attached to the sides of your head.

User avatar
karatestu
Posts: 4787
Joined: Sun Jan 08, 2017 4:40 pm
Location: North Yorkshire
Has thanked: 1047 times
Been thanked: 616 times
Great Britain

Re: Doc modding Marantz imperial 7

Unread post by karatestu »

Geoff.R.G wrote: Sun Aug 29, 2021 10:14 pm
karatestu wrote: Sun Aug 29, 2021 9:54 am Just when you thought (hoped) that this ridiculous thread had quietly fizzled out into an eternal state of nothingness it pops back up like a turd in the bath.

If anybody here thought that I actually knew what was going on then I hate to have to tell you that I haven't a fecking clue. Led by donjeys would be a good way to describe it :grin: Just like this ridiculous government- I feel as useless as the Rt Hon Gavin Williamson the education secretary. This endeavour will ultimately waste a lot of tax payers money and end up getting binned due to being unfit for purpose. There was a glimmer of hope but the prospect of actually pulling this one off is going to need metal tits and will probably be about as hard as trying to convince the climate change denying mormons that human activity really is to blame .

I am now completely convinced that this whole thread has been planted in my mind by Russian agents with the sole purpose of causing confusion in the multi billion pound UK subjective music appreciation industry. I now urgently need to purchase a microphone and software to measure the frequency response of these speakers. It's all very well and good rewriting the laws of physics but nobody is going to believe me without some lovely graphs showing frequency response, impedance, directivity, group delay and phase.

Live long and prosper.
The moment you take measurements it ceases to be subjective and becomes objective. If you don’t know how to use the software the results won’t even be objective but speculative. Save your money and use the two highly sensitive instruments attached to the sides of your head.
Happy Bank Holiday Geoff. My post was in jest, I have no intention of ever measuring anything. I agree it would be speculative if I did. I don't have the time or inclination to learn how to do it properly. It's either do it properly or not at all.
DIY inspired by Richard "The Doc" Dunn RIP

User avatar
Latteman
Posts: 955
Joined: Tue Aug 14, 2018 7:20 pm
Location: S. Yorkshire
Has thanked: 259 times
Been thanked: 101 times
Contact:
Great Britain

Re: Doc modding Marantz imperial 7

Unread post by Latteman »

I’ve been busy
Image
Image
These users thanked the author Latteman for the post (total 3):
CycleCoach (Fri Sep 03, 2021 12:58 am) • antonio66 (Fri Sep 03, 2021 1:45 am) • Grumpytim (Sat Sep 04, 2021 12:45 pm)
Analogue Source -
Diy Turntable ,- Thorens Td321 donor
Diy tonearm- Well Tempered clone,
Benz Micro Silver
Hitachi HT-660, Ortofon vivo blue
Phono 1 (160va) & Ortofon MCA10
Digital Sources- MF M1 Clic, Diy IDE cdp, iPhone 6s.
Amplification 2x Nva A20; A30 mk2; AP10H; Khozmo passive pre
Speakers- Diy ‘Bipolar 5.25” in bamboo sphere ; Ls6/3
Dc blocker to Nva mini BMU

User avatar
karatestu
Posts: 4787
Joined: Sun Jan 08, 2017 4:40 pm
Location: North Yorkshire
Has thanked: 1047 times
Been thanked: 616 times
Great Britain

Re: Doc modding Marantz imperial 7

Unread post by karatestu »

Latteman wrote: Thu Sep 02, 2021 5:35 pm I’ve been busy
Image
Image
So what's this Peter ?

Is your mid bass down firing only ? It's more important imo to get the tweeters in a sphere than the mb but depending on your xover frequency it probably is still worthwhile.

You certainly have been very busy. So how does it sound then ?
These users thanked the author karatestu for the post:
savvypaul (Fri Sep 03, 2021 1:00 pm)
DIY inspired by Richard "The Doc" Dunn RIP

User avatar
Latteman
Posts: 955
Joined: Tue Aug 14, 2018 7:20 pm
Location: S. Yorkshire
Has thanked: 259 times
Been thanked: 101 times
Contact:
Great Britain

Re: Doc modding Marantz imperial 7

Unread post by Latteman »

I am looking for a tweeter housing, half a sphere is likely.
Yes down firing 5.25” driver from Royd minstrels so lightly doped.
I’m pleased with the bass response and tweeter unit borrowed from my larger speakers integrates well.
There is nothing to dislike about the sound. The reason for the configuration is that’s how I positioned it to paint- I was planning to put another 5.25 driver firing up but will keep as is for now.
The biggest problem is what to use as a stand without making it look like a space ship or an alien robot
Analogue Source -
Diy Turntable ,- Thorens Td321 donor
Diy tonearm- Well Tempered clone,
Benz Micro Silver
Hitachi HT-660, Ortofon vivo blue
Phono 1 (160va) & Ortofon MCA10
Digital Sources- MF M1 Clic, Diy IDE cdp, iPhone 6s.
Amplification 2x Nva A20; A30 mk2; AP10H; Khozmo passive pre
Speakers- Diy ‘Bipolar 5.25” in bamboo sphere ; Ls6/3
Dc blocker to Nva mini BMU

User avatar
Latteman
Posts: 955
Joined: Tue Aug 14, 2018 7:20 pm
Location: S. Yorkshire
Has thanked: 259 times
Been thanked: 101 times
Contact:
Great Britain

Re: Doc modding Marantz imperial 7

Unread post by Latteman »

Little update
Making bespoke stands
Moved tweeter unit to below the mid bass- both now at listening height
Bass response is good- pleased
Listening to the details now- previously with tweeters on top the fine detail was really good- quieter background I suppose

Image
These users thanked the author Latteman for the post:
karatestu (Fri Sep 03, 2021 6:35 pm)
Analogue Source -
Diy Turntable ,- Thorens Td321 donor
Diy tonearm- Well Tempered clone,
Benz Micro Silver
Hitachi HT-660, Ortofon vivo blue
Phono 1 (160va) & Ortofon MCA10
Digital Sources- MF M1 Clic, Diy IDE cdp, iPhone 6s.
Amplification 2x Nva A20; A30 mk2; AP10H; Khozmo passive pre
Speakers- Diy ‘Bipolar 5.25” in bamboo sphere ; Ls6/3
Dc blocker to Nva mini BMU

User avatar
karatestu
Posts: 4787
Joined: Sun Jan 08, 2017 4:40 pm
Location: North Yorkshire
Has thanked: 1047 times
Been thanked: 616 times
Great Britain

Re: Doc modding Marantz imperial 7

Unread post by karatestu »

Latteman wrote: Fri Sep 03, 2021 6:23 pm Little update
Making bespoke stands
Moved tweeter unit to below the mid bass- both now at listening height
Bass response is good- pleased
Listening to the details now- previously with tweeters on top the fine detail was really good- quieter background I suppose

Image
Well done Peter. As you are finding out , it is an enormous amount of fun playing about with speakers and trying unorthodox designs.

Did you make the enclosure yourself ?
DIY inspired by Richard "The Doc" Dunn RIP

Post Reply