World-Designs-Forum  

Go Back   World-Designs-Forum > DIY Projects > Amplifiers
Register FAQ Members List Calendar Gallery Today's Posts Mark Forums Read

Amplifiers Your DIY amplifier designs

Reply
 
Thread Tools Display Modes
  #1  
Old 15th September 2020, 01:48 PM
bob orbell bob orbell is offline
Senior Member
 
Join Date: Nov 2009
Location: kettering northants.
Posts: 2,734
Question Best £100 Upgrade

Hmm, you would be much better off spending the £100 on a fully regulated power supply, for pre and especially phono. A couple of metres of fancy cable for £100 is to me crazy, just try removing the cable, clean both connector ends and refit, it will sound cleaner, that is what happens when you by that fancy cable, everything is clean, just think about what Pre 65 wrote, it makes sense. Bob
Reply With Quote
  #2  
Old 15th September 2020, 04:11 PM
colin.hepburn colin.hepburn is offline
Super Moderator
 
Join Date: Jan 2006
Location: Newtonhill Aberdeenshire
Posts: 2,721
Default Re: Tweaking Sextets.

Hi All
Well, I didn’t want to get into this debate again but here I am ho well

Yes, I would also agree with what pre 65 said and would follow up with what Bob has advised. You on Chris. In fact that’s what I am working on right now rebuilding my PSU3s with regulated outputs and using one PSU for the preamp and the other for the phono.

HO. And I could go the whole hog and wrap all my cable in tin foil and wear a safety pin peter belt style.
The Regulated PSU is a no brainer and spend the cash you save on cables on some new music

This is just my point of view others may differ and do it their way that’s fine to
Colin
__________________
The Blues man

Turntable Rega 3 custom RB250 with ortofon 2M Blue /other goldring 1042 /WD phono2 /WD CF pre custom converted /WD psu2 /home built JE Labs Single Ended 6SL7/KT66/Speakers Frugal horns Mk1s
Other turntables AR EB101/Thorns TD150mk2/Thorns TD160mk2


If you have trouble reading my posts its because I am a dyslexic member
Reply With Quote
  #3  
Old 15th September 2020, 04:42 PM
bikerhifinut bikerhifinut is offline
Senior Member
 
Join Date: Jan 2006
Location: Penrith, Cumbria
Posts: 1,128
Default Re: Tweaking Sextets.

Quote:
Originally Posted by colin.hepburn View Post
Hi All
Well, I didn’t want to get into this debate again but here I am ho well

Yes, I would also agree with what pre 65 said and would follow up with what Bob has advised. You on Chris. In fact that’s what I am working on right now rebuilding my PSU3s with regulated outputs and using one PSU for the preamp and the other for the phono.

HO. And I could go the whole hog and wrap all my cable in tin foil and wear a safety pin peter belt style.
The Regulated PSU is a no brainer and spend the cash you save on cables on some new music

This is just my point of view others may differ and do it their way that’s fine to
Colin
Time this was split off the current thread I think?

Now then, I think I am to blame for Bob's enthusiasm for regulated HT PSUs on preamps as I think it was my experience with my phono stage that started it all off about 5 years ago.
So my quids worth:
My take on things is that you have to have a sound (ooops pun) circuit design to start off with, this includes the PSU as all an amplifier does is modulate the power its given so to speak.
So starting with an APPROPRIATE PSU design is vital, we can all agree on that I hope.
Then you gotta choose a decent circuit design for the amplifier. There are some weird ideas out there.
Circuit layout, and attention to earthing/signal ground routing is again vital, including the heater wiring, even DC regulated heaters are NO EXCUSE for sloppy wiring runs. Given that a good layout isn't always the neatest, usually a scruffy job works like a scruffy job. No amount of fancy wire or bacofoil resistors and virgin olive oil dielectric capacitors will save you here.
Get all that right and you can think about using different component technology and construction, I don't get hung up on this part as I personally find the differences to be subtle, if I can hear them at all some times.
Just use good quality suitable parts with appropriate voltage and power ratings.
Once you get all that working and its measuring within its design parameters and is sounding correct, then you can have a think about the various passive and active devices in a circuit.
If you feel you need to alter a component either in value or construction, do it one part at a time, most of us of course know all this but I feel its worth laying down the ground rules.
Do a bit of basic homework, the rewards when you actually understand what each part of a circuit does are much greater than merely swapping bits at random. Again I think most of us here would agree there.
Once you've got your amp or device running nicely, then you can play around with bits of wire, potentiometers, plugs and sockets,
Finally don't be upset when you don't hear a difference and be ready to admit it, we don't all have golden ears and I think we all perceive music and sound differently anyway. Also don't discount the placebo effect when swapping something out as its natural to expect a difference, indeed an improvement. Bob's theory of the wiping clean of contacts when swapping wires in and out certainly has something reasonable and credible about it.
if you're all still awake, lets not all fall out but also try and keep a sense of proportion.

Andy

Last edited by bikerhifinut; 15th September 2020 at 06:29 PM.
Reply With Quote
  #4  
Old 16th September 2020, 02:20 PM
bob orbell bob orbell is offline
Senior Member
 
Join Date: Nov 2009
Location: kettering northants.
Posts: 2,734
Default Re: Best £100 Upgrade

Hmm someone moved this post, who I wonder, speak now or forever hold your piece, and I don't mean holding that . Bob
Reply With Quote
  #5  
Old 16th September 2020, 03:00 PM
Richard Richard is offline
Super Moderator
 
Join Date: Dec 2005
Location: Notts
Posts: 5,357
Default Re: Best £100 Upgrade

Quote:
Originally Posted by bob orbell View Post
Hmm someone moved this post, who I wonder, speak now or forever hold your piece, and I don't mean holding that . Bob

haha yes of course it was me, at the suggestion of Andy, as it was waaaay off topic... now you can chat away about regulated psu to your hearts content without disturbing Stuart
Reply With Quote
  #6  
Old 16th September 2020, 04:42 PM
bikerhifinut bikerhifinut is offline
Senior Member
 
Join Date: Jan 2006
Location: Penrith, Cumbria
Posts: 1,128
Default Re: Best £100 Upgrade

Cheers Richard

Now then, we all agree a good PSU design is at the heart of a successful audio project.
Just to muddy the waters a bit, It isn't always necessary to go the whole regulated hog.
Power amplifiers are the obvious case in point.
And dare I say it an awful lot of line level preamps, (not all), really don't need to have their HT nailed down quite so rigidly and I would usually start with a conventional CLC or even CRC filtered supply especially those designs with inherently good PSRR.
Regulated HT is, for me, kind of essential for a tightly specified MM or MC RIAA preamp. It takes out one important variable. But we need to look at disc stages in more depth after this as after reading my M Jones books I realise that the EQ network design is fraught with complications that make my head spin. Things like Miller effect which can cause deviations from an ideal EQ curve and this can vary from valve to valve specimens etc. I got to thinking about the use of 5751 in place of ECC83/12AX7 for instance in Phono3, what you are doing here is using a lower gain Valve which will have an effect on the input capacitance due to Miller effect. So dare I postulate that those who prefer the 5751 are actually expressing a preference for a different EQ curve, which may or may not be closer to the ideal.
If you like that of course it is the only thing that matters, perceptions and hearing acuity being different for each one of us.
Ok enough cats amongst pigeons for now, I'm still using ordinary standard PVC insulated solid core copper for internal hard wiring unless I need a heavier rated wire in a part of a circuit. Likewise I use very ordinary stranded PVC insulated speaker wires, admittedly in a run just less than 2m, the length of speaker wire, I feel has more effect than most other parameters.

Andy.
Reply With Quote
  #7  
Old 16th September 2020, 04:55 PM
bob orbell bob orbell is offline
Senior Member
 
Join Date: Nov 2009
Location: kettering northants.
Posts: 2,734
Default Re: Best £100 Upgrade

Funny you should bring up Phono stages and RIAA Andy, to that end, I am looking at JB's stages and may try one latter, but first I am awaiting a new Ortofon Cadenza Bronze, should be with me tomorrow . Bob
Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT +1. The time now is 03:56 PM.


Powered by vBulletin® Version 3.7.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright World Designs