Ageing valve fan seeking upgrade

Hi all,

I have been using valve power-amplification for the last 20 years, and I have been in a happy rut, first with an original Radford STA25, then for the last decade with the modernised version - the "Renaissance" which is better-looking, self-biassing and I believe a little more powerful. I really enjoy it and hesitate to change, but.....

It's in for minor repair at the moment, and listening to the temporary (old) Sansui substitute I noticed that although relatively "dead", it has slightly better mid-range detail. It has made me wonder about possible alternatives. I don't have money to throw at the question, so would still be probably looking at S/H. Thought about a Beard P100 that is on e-bay.

But also thinking about these new chinese options - noted the cautionary tales about AVC, but wondering about Icon and also about Prolog 4. Is there anyone who could suggest what might be out there that would give me an improvement, or worth trying at least? Or convince me to stay put even?

And does anybody have any idea what a Radford Renaissance is worth? This would largely determine my budget for the change. I believe most of the originals went to the Japanese market. It's been very well cared for. Maybe I will have to curb my impulses, but you know what it's like when the "itch" gets you!

Jon

 

I wouldn't. The more powerful Beards are prone to causing problems.

I had a Beard P35 that was good enough, but unless you get it for under £250ish I'd look at something else personally.... like a second hand WAD kit or an imported amp..

 

Are you an ageing fan or do you like ageing valves? It's not clear

 

You could consider getting the Radford rebuilt by someone who knows what they are doing. If going for a new one, the Prima's are hard to beat at the price. There are quite a few WAD amps cropping up on ebay at the moment. Built properly these are great amps though your taking a risk buying one 2nd hand. Also, keep in mind that WAD seems to have ceased trading so back-up may be thin on the ground if your not familiar with a soldering iron. Id have a listen to a Prima.

 

Answer is probably both . Well I'm not very old really - still a decade off OAP, but it appears to be the older amp designs I've liked - but then that's because the new ones weren't there twenty years ago I suppose.

Are any of the designs really new, or are they just new builds / components etc?

So now I am in a hole I will stop digging.

Jon

 

"You could consider getting the Radford rebuilt by someone who knows what they are doing"

Thanks for your response T-Bone.

Do you mean that you think my current Radford is performing below capability, or that it needs some kind of mod? If the latter, what would you suggest it needs. I do have a local guy who I believe does know the business and the amp is with him now.

Jon

 

here's a few to look at that would give you something special.

£800-£1300.


http://cgi.ebay.co.uk/World-Audio-3...5849343551QQcategoryZ3280QQrdZ1QQcmdZViewItem

http://cgi.ebay.co.uk/CARY-AUDIO-30...5847884440QQcategoryZ3280QQrdZ1QQcmdZViewItem

http://cgi.ebay.co.uk/Superb-Audion...5850356681QQcategoryZ3280QQrdZ1QQcmdZViewItem

 

Well, Ive never heard one so I cant comment personally but a know a few who have and they all rate them highly. If the amp still has the original components (capacitors, resistors etc) then replacing these with modern equiv's would be worthwhile I would have thought. There maybe 'mods' to be done, a few hours on google would be worthwhile.

Of those bottleneck has listed Id be tempted with the WAD 300b's plus the preII he's selling in a seperate auction.

Personally, if it was mine I'd be looking at refurbishment, I feel it would be worth it.

 

Jon

From what I have seen in an internet auction and vintage hi fi dealer stock lists, any vintage Radford valve amplifers such as the STA15 and STA25 go for 500 pounds minimum. Even your Renaissance STA25 is over 20 years old, so I would also call it a vintage Radford amp.

I have heard the STA15 with a GZ34 valve rectifier rather than the solid state diodes used in STA25 or your Renaissance 25. The STA15 is one of the best vintage valve amps I have listened to. It sounds much better than a modern Woodside STA35 when both amps were auditioned using a pair of Quad ESL57. I have never heard the Renaissance STA25, but I guess the output transformers are as good as the original STA15 or STA25. As long as the electrolytic caps have been changed and the resistors are still in spec, your Renaissance 25 should be a very fine amp even nowadays.

There is a Yahoo group about Radford amps run by Carl Jones. You will get a lot of valuable information about your amp.

Just my humble opinion.

Regards
Hon

 

Being the owner of the STA35, I have to say they sounded different

The STA15 is the wonderful classic rich sound that you would expect, but sounding a bit slow. The STA35 was pacier and more rhythmical, but lacked that special something that the STA15 has in spades. Interestingly the STA25 was a nice halfway house.

So don't be in a rush to dump the Radford, you will find it hard to get a better replacement.

 

Thanks everybody for the information you are giving - it is all very helpful.

For the record, my amp is a Woodside device and so has "modern" componentry on a PCB, and I believe is diode rectified. I believe that mine was a pre-production model (it has serial no. 00011) and the label says STA025, but I believe that it is the same as was later marketed as STA035 (or something like that). It was checked out by Woodside in the mid-90's and brought up to whatever was then regarded as "spec".

I am beginning to feel that I need to try and work with this amp - that for the amount of money available I will not easily be able to improve on it. I doubt that the PrimaLuna will deliver enough of an improvement, though I might see if I can get to try them side by side. I like the suggestion of the WAD monoblocs, but with only £500 coming back on the Radford it's not in the £££frame.

So if there is anyone out there who knows what might be worth doing to improve it (particularly in midrange detail) I would be very appreciative of the advice. Does anyone have a link to the Carl Jones website?

Many thanks to all,
Jon

 

Lee: Hope you haven't taken my opinion being offensive . To be honest, your STA35 didn't have enough time to warm up during the Leak fest. I was in Hong Kong in November and listened to a pair of vintage Klangfilm EL34 push pull amps. They really sounded terrible for the first hour. My friend told me that they required a couple of hours to warm up and that was very true. After warming up, the midrange was glorious with very deep bass.

Jon: You can find the yahoo Radford group using this link: http://groups.yahoo.com/group/radford/. In the "photo" section of the yahoo group, you will see some literature and photos of the STA25 Renaissance.

I have attached a photo of a Woodside STA35, does your amp look like it?



By the way, Lee is the founder or the Quad yahoo group, many members cross post in the Quad, Radford, Leak, LS35a, Spendor yahoo groups.

Best wishes
Hon

 

Hon

No worries, I know the spirit of your post are always for the good.

Jon I have a schematic, which I can photo for you if you want. I'm in two minds like you. I don't feel anything at about £500 would be an improvement, so maybe tweaking is the answer. Maybe PIO coupling caps may help. I'll have a look at the schematic, as maybe a change to the feedback cap/resistor and gridstop resistor may help.

 

Yes Hon, that is exactly what it looks like.

Lee, a schematic would be a valuable thing to have, and any suggestions will be very welcome.

Jon

 

Have you tried different tubes in it?
Especially the input stage ones can have a massive difference to the sound. You might be able to get much better mid detail by this alone.
I'm not sure what tubes your amp takes.
Sylvania and RCA 6SN7's are my current favourites.

 

I'd second that, having recently replaced Golden Dragon ecc82's with nos RCA black plates - quite a big difference, mostly in highs tho'.

 

Thanks Steve and La T,

The originals were mullard ECC81 and ECF82 I believe. Don't have the amp with me, but think that I have equivalents in there now for the ECC81's - 12AT7 comes to mind. Having looked at some sites, 6SN7 doesn't look like an equivalent, but LT you're saying you've replaced ECC82's? Is this in an STA25?

BTW La T, where in Somerset are you? I'm just South of Salisbury

Jon

 

Hi Jon,

No, sorry for my slightly misleading post, I don't have an STA25, I have a Copland, I was just agreeing with speedy.steve's suggestion that playing around with alternative valves can make a significant difference.

I'm in Yeovil btw.

 

Jon

I have posted some info on the Radford Yahoo group.