A Valve Preamp with Phono Stage and Tone Controls.

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JamesD
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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by JamesD » Mon Sep 14, 2020 8:11 pm

Here you are for QUAD style tilt controls implemented with valves - Tubecad of course :D

https://tubecad.com/2013/06/blog0266.htm

JRB links to some of his other sonic controls too.

James

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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by Cressy Snr » Mon Sep 14, 2020 9:22 pm

JamesD wrote:
Mon Sep 14, 2020 8:11 pm
Here you are for QUAD style tilt controls implemented with valves - Tubecad of course :D

https://tubecad.com/2013/06/blog0266.htm

JRB links to some of his other sonic controls too.

James
Interesting :)
And the link makes great reading. Thanks James.
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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by izzy wizzy » Tue Sep 15, 2020 7:30 am

As far as I can make out, you haven't got tone controls up till now. So why now?

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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by Cressy Snr » Tue Sep 15, 2020 11:04 am

izzy wizzy wrote:
Tue Sep 15, 2020 7:30 am
... So why now?
I just fancy building a preamp with them. It’s something new to learn about. I’m also sick of the stark, warts ‘n all presentation coming from my oldies collection.
When you like old 60s pop records, both digital and vinyl, 60s soul, 50s rock’n roll, I’ve come to the conclusion that some degree of tone control is essential. I’ve done all I can over the years to get this stuff to play well on the system, and have succeeded admirably, but it needs the tone facility to get the very best out of these records, there’s no hiding from it.
The tilt control will probably be the best option.
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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by izzy wizzy » Tue Sep 15, 2020 11:19 am

I wonder why those records need help. Was it the taste of the times to master records that way? Coz in other genres, say classical, there are some of the great recordings from Mercury, RCA, Decca to name a few. Just wondering. I just assume they're meant to sound that way but we can't go back in time to find out.

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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by JamesD » Tue Sep 15, 2020 12:06 pm

Here are two documents that explain why one might want to tweak tone and tilt controls on records from the past...

http://pspatialaudio.com/record_characters.htm

http://pspatialaudio.com/Pspatial_EQ_Guide.pdf

Paul's championing of a 'loudness eq' switch is another reason when listening at low level.

In the RIAA era I find that some records are mastered in a way that, to me, gets in the way of the music and then I like to apply some tweaking to them to make them listenable to my ears - my favourite example of this is some of Tom Petty's work that I find uncomfortably thin sounding before tweaking but really like after tweaking.

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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by Cressy Snr » Tue Sep 15, 2020 12:22 pm

izzy wizzy wrote:
Tue Sep 15, 2020 11:19 am
I wonder why those records need help. Was it the taste of the times to master records that way? Coz in other genres, say classical, there are some of the great recordings from Mercury, RCA, Decca to name a few. Just wondering. I just assume they're meant to sound that way but we can't go back in time to find out.
My argument is, how do we really know how a record from those days was meant to sound? Common or garden, domestic replay equipment in the 1950s and 60s would have been all warm, cuddly, one-note bass, and rolled off at the top; at least my parents’ radiogram was.

The pop studios would have known that their product was mostly destined to be played on those lo-fi pieces of equipment, whereas the classical and to a lesser extent, the jazz market would have been more affluent and a lot of those people would have had stereo on proper hi-fi systems, hence all the fab recordings of classical and jazz from that era.

So if you had a warm, rolled off piece of gear as your destination then as an engineer, you’d boost the upper mids and lower treble to make your product sound reasonable. You wouldn’t have needed much bass because of all the thin, plywood, radiogram open back enclosures adding their own versions of the low end. And on your teenage bedroom Dansette portable, you wouldn’t have heard the bass anyway, so as an engineer, why put it in?

Paul Mc Cartney famously complained that the EMI engineers wouldn’t allow his bass parts to be as loud/deep as he wanted them and it wasn’t until the White album was being recorded that he started to get what he wanted in terms of the bass from Beatles records. And you can hear that progression if you have all the Beatles albums.

When this old pop stuff gets digitally remastered, there is this nonsense about preserving the original recording as closely as possible. Don’t they get that most of it was eq’ed to sound good on radiograms? Put it through a modern tone-control-less hi-fi and some of it will take your head off. A nice tilt up the bass/drop the treble tweak of a tone control will make these recordings much more palatable. And why not?

For me it’s now become about enjoying as much of your music collection as possible. Why put up with thin and bright when for donkey’s years there has been the facility to dial it out.
Last edited by Cressy Snr on Tue Sep 15, 2020 12:58 pm, edited 2 times in total.
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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by pre65 » Tue Sep 15, 2020 12:37 pm

Cressy Snr wrote:
Tue Sep 15, 2020 12:22 pm

For me it’s now become about enjoying as much of your music collection as possible. Why put up with thin and bright when for donkey’s years there has been the facility to dial it out.
Bravo. :)
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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by izzy wizzy » Tue Sep 15, 2020 2:17 pm

Thanks for the explanation Steve. I just didn't know hence the question. Wasn't coming at it from any other angle. It's not an era in music that I have much to do with other than classical and the odd bit of jazz. Luckily we live in an era of great reissues of some of the classics albiet at a price but the originals in good condition are even more.

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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by Cressy Snr » Tue Sep 15, 2020 2:42 pm

No problem Stephen. :)
I've finally realised, I need some form of tone control for old 50s and 60s recordings; a realisation that was a long time coming, However from looking at James' links, I'm just grateful I'm not interested in 78s. :lol:
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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by shane » Wed Sep 16, 2020 7:34 am

Careful, Steve! There’s a slippery slope here. A while ago I bought a number of classical albums from a local charity shop. All in beautiful condition, but each one had a curious sort of bar graph carefully drawn on the inner sleeve. After much puzzling, I worked out that they were individual settings for each album for a graphic equaliser. There were even subtly different settings for individual albums in a boxed set. How much work must the guy have put in when he brought home the Beethoven Symphonies on six albums? The mind boggles...

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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by Wolfgang » Wed Sep 16, 2020 4:35 pm

I don’t think simple tone controls are ideal as increasing the bass would also increase subsonic frequencies dramatically, stressing driver and amp unnecessarily.

On the other hand after experimenting for a while with different EQs and comparing the results to using no EQ I think the phono section needs some kind of tone control/possibility to adjust it to the listening room.

I am using now the Drawmer 1974 stereo PEQ and it works very well and is really hardly noticeable if bypassed.
https://www.drawmer.com/products/70s_se ... ric_eq.php

The subtle sound shaping with a PEQ that is normally used as mastering processor does the job without interfering with the original mix in any negative way (not so easy when using graphic EQs).No need for many different settings changing from album to album. Only in rare cases there is a little adjustment necessary in the upper mids between old and new recordings.

I use this setup together with a tube-only phono pre (Fosgate Signature) and the hybrid Audio Research PH3. In both cases I get excellent results with no neg. sound coloration. Btw, Audio Research has released the schematics for the PH3. Considering how good it sounds this could be a nice DIY project for very little money compared to the original price for the finished product.
https://www.arcdb.ws/model/PH3

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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by Cressy Snr » Wed Sep 16, 2020 10:53 pm

I believe the circuits I’m drawing up at the moment, break international audiophile law in a very specific and limited way, and are merely insurance policy against a possible no deal screech fest caused by a 60s recording mixed for a console unit. I don’t necessarily like to have to propose these controls, but our friends need to understand ABSOLUTELY...that if I’m forced to do so, I’m giving them notice that I mean what I say, and let them be in no doubt....I WILL use them! I know I signed an agreement in 1985, not to interfere with the original mix, but needs must .

Details will follow in due course. I’m being led by the science, I was testing my eyesight, and if these tone ccts over promise and under deliver, I’ll blame somebody else and will lock the controls down flat. Wiffle woffle, piffle, puffle, fuck business, bblgh!
Last edited by Cressy Snr on Thu Sep 17, 2020 7:19 am, edited 1 time in total.
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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by Paul Barker » Thu Sep 17, 2020 7:17 am

Cressy Snr wrote:
Tue Sep 15, 2020 2:42 pm
No problem Stephen. :)
I've finally realised, I need some form of tone control for old 50s and 60s recordings; a realisation that was a long time coming, However from looking at James' links, I'm just grateful I'm not interested in 78s. :lol:
We need tone controls for old ears.

My work van with a crap audio that the young lads love gets treble turned down and bass up so I can tolerate the awful quality of the radio and the reproduction. But peace and quiet sounds better.
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Re: A Valve Preamp with Phono Stage and Tone Controls.

Post by Ray P » Thu Sep 17, 2020 7:34 am

HI Steve. I saw these and thought of your project...

https://www.diyaudio.com/forums/tubes-v ... ost6329014

post #24 too.

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