Vr 70e

So knowing my liking for audio on the cheap .......What do people think of these amps ?

http://www.apah69.dsl.pipex.com/dynavox/dynavox.htm


Is the 5881 a straight swap for the el34 ?

The price of a little over £200 shipped these seem a bargin hard to turn down ......or am I missing the obvious.

 

I have one!

 

and............................?

 

..............and what? oooooh right I see well :0P

I like it alot, I bought one as a taster for valves and something to have a play with, it took all of 20 mins to realise it was far superior to my amp at the time (a marantz 6010ki) and my brothers 7200KI. That was in standard form, since then Ive played around with it. Ive tried numerous input tubes and settled on Mullards. Im still using EL34's though they're svets now. Tweaks wise Ive recapped (I have a schem), bypassed the power caps, removed two caps (v. good mod), biased the heater windings to 25V (thanks to T's advice), shunt mod to a Blue Alps and changed to triode connection, oh and silver wiring. Oh and new rca sockets (the std ones are total pants). I do run mine with a heavily modded MF X-DAC, it loses some clarity but gains more gusto's if you get my drift.

The only speakers its sniffed at was my mates 805's but it was in a large room and I didnt take the preamp, even so he much preferred it to the Quad II's another mate has. I will at some point try KT88's.

 

Hi-Fi World reviewed this (very positively) about six months ago.

At the price, you probably don't have anything to loose

DT

 

kt88 a straight drop in ?

 

Should be, Ive read more than enough on the DVM, if not theres just one resistor to change.

 

look like I may have a punt at at least one of these.

 

Wise choice sir. Ive got the schematic if you want it. I'll list what Ive done too.

 

That would be great ...thanks..


either pm or email me

 

I'll mail it you, pm me your email addy.

 

This looks like a great deal, let me know how you fare with it. I still want the phono stage upgraded by the way, just got too many other more important things on the go right now

 

Hello all first post here!

I am thinking of buying this amplifier. Just having a look around the net it uses EL34 tubes on the power stage and CF2s as drivers. Anyone know of any direct replacements for this tube? As it seems to be pretty hard to find.

Any help would be much appreciated,

Thanks.

 

Blimey! the output transformers alone in my valve amp cost more than £200
I'm not sure if you can just stick KT88's into that amp, it depends if the trannies can take it

 

CF2=ECF82. Loads around, have a look for Mullard NOS on ebay. I have quite a few different brands.

They take KT88s easily.

 

Ok guys went ahead and ordred one, I will post impresions when I get it. Also T-bone Sanchez is it possible to get a copy of that schematic?

Cheers.

 

No worries, pm me your email addy and I'll post it over with a list of mods Ive done.

 

I have bought one of these recently too, won't get to try it until the weekend though.

I am sure I read somewhere, I thought it was through the link zanash posted, that there was a problem with some resistor values causing the valves to fail quicker than they should. Wheover wrote it suggested changing them, I am just imagining this or is it the case?

Apparently my one has been upgraded with Russian 5881's (Sovtek EL34EH) tubes, don't know whether this is good or not, like many other people I got this amp as a taster for valves.

T-bone Sanchez, I don't suppose I could get a copy of your schematic and mods too could I? Eventually I will probably modify it.

Many thanks
Ian

 

Im not aware of any problems with the resistor values on this model and theres nothing to suggest otherwise. There are issues with some Ming Da's and another Chinese amp I cant remember the name of at the moment, might be Yaquin.

The 5881's predate EL34's and they seem to offer a more traditional valve sound, not unlike the KT66's I believe. Personally I think the KT88's would be the upgrade valve wise. The 5881's do run on a higher voltage than the EL34's so check this before swapping valves around (biasing is dead easy though). If your going to mod, then this is a great starter.

If you pm me an email addy I'll send the schem over and a list of mods Ive done if you want it.

 

Cheers for the info. As far as I can tell the 5881's will have been installed already, but as you suggest I will check the bias first.

Thanks
Ian