Valve compressor and mains voltages

[Richie Royale]

http://media.soundonsound.com/sos/nov10/images/thermionic_littlebustard_02.jpg

Same picture, but bigger resolution. Click on it to zoom in if you are on a smaller monitor.

http://media.soundonsound.com/sos/jan10/images/thermionic_fatbustard_02.jpg

Another one.

[SafeandSound Mastering]

The choice of knobs on these devices is awful for what is a very expensive compressor. (Sure I know, listen don't look but...£3K +) I have been seriously considering another high end valve compressor (something more coloured than my Summit DCL-200)and I am not impressed by the visual aspect of these devices from the outside. I was thinking "They must have spent the money on the inside". This has been an interesting read.

SafeandSound Mastering

[ef37a]

Thanks,
Still hard to tell if it has DC heaters but I can see no evidence of any regulation,HT or heaters.

I suppose the construction is well...Ok. "Fender circa 1970"? I would expect these day to see all the power supply components sans transformer on a decent pcb.

Dave.

[Folderol]

Thanks for the detailed pix. That power supply is a house of horrors!

The heaters are in fact DC. There are 4 diodes in a bridge configuration (you can see them quite clearly if you zoom in). However, they are actually 8 diodes wired in parallel pairs - something you should never do under any circumstances!

Above the ceramic resistor is one of those little circular 1 amp bridges bodged onto the tagstrip. This is obviously for the HT

As Dave said, there is absolutely no attempt a voltage regulation - not even crude mains tappings. And why have the put screening round the mains Tx, which is well away from everything else, but none round the power switch right beside signal switches.

I notice the transformer hasn't been very well fitted - it's sitting to one side of the dished washer.

Apart from what looks like a fuse carrier between the power switch and the transformer there appears to be no protection, and no spike/EMI suppression.

Main PCB looks like cheap paxolin rather than a GRP one - a decision that can only be described as 'quaint'.

All in all, nothing like what I'd expect for 2k - especially including those bargain basement pot knobs.

[wave1]

Thanks again chaps - all useful stuff. My friend will get to Maplins for one of these gizmos asap, I'll update the post once we get some results. Had a look for some gut shots of the Phoenix online, but nothing doing, so I'll try to get some if anyone is interested - won't be able to do it till next week though.

Cheers

[James Perrett]

I suppose the construction is well...Ok. "Fender circa 1970"? I would expect these day to see all the power supply components sans transformer on a decent pcb.

Hand made point to point wiring is a big selling point for these things. It may have kept the radio/TV repair trade in business during the 50's and 60's but I'm not sure I want that type of construction in a working studio - unless it is done really well.

James.

[Hugh Robjohns]

For info, I have invited Thermionic Culture and/or their agents to comment and am awaiting a response.

hugh

[ef37a]

I suppose the construction is well...Ok. "Fender circa 1970"? I would expect these day to see all the power supply components sans transformer on a decent pcb.

Hand made point to point wiring is a big selling point for these things. It may have kept the radio/TV repair trade in business during the 50's and 60's but I'm not sure I want that type of construction in a working studio - unless it is done really well.

James.

Yes James, peeps love to see "hand wired" in guitar amps too and some think it adds to the sound quality.
In truth the things are FAR more consistant when build on pcb's. I personally think you get a better product at a cheaper price and/or you can put in more features apt to the modern player such as FX loops and MIDI.

Dave.

[Mixedup]

peeps love to see "hand wired" in guitar amps... In truth the things are FAR more consistant when build on pcb's.

I'd like it if my Twin had been hand-wired, as the PCB traces which raised off the PCB wouldn't have required tracking down and repairing There are pros and cons to both approaches.

[Tomás Mulcahy]

Badly chosen PCB materials- they forgot about the heat inside the amp. It doesn't follow that all PCBs are "bad".

[ef37a]

Just clocked the gutshot of the Ingram pre' page 176 March issue.

Now THAT'S the way to make a power supply in the 21st century TC!

BTW, early days but the March issue looks virtually as well stuffed as Febs!

Dave.

[Hugh Robjohns]

Yep, there's no doubting that you get what you pay for in the Ingram. Beautifully designed. Shame about the silly production wiring cockup and incomplete QC, but easily resolved and I'm confident that the company has addressed that particular weakness.

Also glad that you're finding so much to enjoy in each issue, Dave

hugh

[Red Mastering]

The choice of knobs on these devices is awful for what is a very expensive compressor. (Sure I know, listen don't look but...£3K +) I have been seriously considering another high end valve compressor (something more coloured than my Summit DCL-200)and I am not impressed by the visual aspect of these devices from the outside. I was thinking "They must have spent the money on the inside". This has been an interesting read.

SafeandSound Mastering

I am also looking for a vari -mu type compressor, and considered thermionic, but it's a bit out of my range (money) and this thread is a bit eye opening too....
here :
http://www.igsaudio.pl/index.php?option=com_content&task=view&id=5
is a guy in Poland who builds many professional audio tools, and also prices are on the 'indie' side:)
many studios in Poland (and not only - check GS -there are happy folks in US too) use his gears and they love it,
I myself got ssl4k 'wannabe':) and it's wicked buss comp
I am considering to get one (vari mu), (I am not reseller or sth.) just dropped that link so you can check it yourself,
good luck!

[wave1]

Hi all - just got the first voltage readings from my friend - seems to vary between 241 and 245 so far, well within spec I would have thought!

Cheers

[Hugh Robjohns]

For a mains supply, yes, that's well within the spec, although obviously a little on the high side of the nominal 230V. Probably because he's either close to the local substation transformer or the thing has been left on a higher tap for some reason.

The variation is only 1.6% though, which isn't a lot. Has he been able to correlate 'good' and 'bad' sound with those 'high' and 'low' mains input voltages?

Hugh

[wave1]

I think his issue is not that it sounds bad, but that it sounds different at different times! He has been somewhat reassured by other people's experience that these things are inherently inconsistent and that it's not just him losing the plot....

[Martin Walker]

For info, I have invited Thermionic Culture and/or their agents to comment and am awaiting a response.

Did they get back to you Hugh?

Martin

[Hugh Robjohns]

Disappointingly, no! I had an acknowledgement of my invitation for them to join in, but nothing since.

Hugh

[Richie Royale]

They probably read the thread and got cold feet!

[Matt Houghton]

http://www.igsaudio.pl/index.php?option=com_content&task=view&id=5
is a guy in Poland who builds many professional audio tools, and also prices are on the 'indie' side:)
many studios in Poland (and not only - check GS -there are happy folks in US too) use his gears and they love it,

Review of the his Tubecore Mastering Edition will hit the shelves with the next issue of SOS. Lovely sounding piece of kit. Missing a few functions when compared with Manley and Thermionic mastering offerings, but it sounds great. Price will be going up a bit as they now have a distributor margin to account for, but it still looks rather competitive.

Not tried this one yet, but it's another possible candidate from a manufacturer with positive feedback in the usual on-line places: Hand Crafted Labs

[ef37a]

Oooer!
I would hate to have to service that Varis device!

"Hand wired" if done with turret board and wireman lacing is nice to see (but still a bit of a PITA to fix and look leaving pristine) but I really do think the whole shebang should be confined now to the "breadboard era" dustbin and folks use ~1.3mm FR4 and heavy copper, plated thru' PCB? Vastley better unit to unit consistancy.

And those meters are a bit "Maplin"?

Dave.

[Cassellah Bailes]

Greetings everybody.

Thermionic Culture are now going to be monitoring user forums to provide any help we can with our products.

This thread alone has a lot of questions, I am going to read back through to answer as many as I can. But please feel free to ask me anything and I will do my best to respond.

Many thanks

Charlie - Engineer at Thermionic Culture

...right now, where do I begin...

[Hugh Robjohns]

Welcome Charlie -- and thanks for getting involved. I'm sure our forum members will appreciate your input.

hugh

[Cassellah Bailes]

Well, I know nothing of the equipment save what I have read in SoS but perhaps someone should send the makers a copy of Nelson Jones' Valve Amplifiers!

Making stabilized heater, bias and HT supplies using modern ICs is pretty simple and would add little to the cost of the units.
Bugger! Were I 30 years younger! I can see an nice little earner there! Will, want a lucrative sideline modding vulture giblets?

I know people want the "sound" of valves but surely the challenge is to keep the sound but use modern techniques to overcome their many shortcomimgs and extend their life?

Dave.

Hi Dave,

We are always developing our products to make them perform better, and yes we certainly do use solid state technology to improve performance. Of course we have our own ethos to valve electronics and design requirements, without them we wouldn't make such great sounding products.

I go to bed with Morgan Jones' Valve Amplifiers every night...

Thanks for your comments.

Regards

Charlie

[Cassellah Bailes]

Disappointingly, no! I had an acknowledgement of my invitation for them to join in, but nothing since.

Hugh

We have recently changed the way we run the business and have only just heard of the invitation. So we jumped at the chance to talk to our end users.

Very happy to be here, thanks for the invite.

Charlie