Mike Frankel Posted November 23, 2003 Share Posted November 23, 2003 Hello All: I need a recomendation for a pre-amp for a Dynaco ST-70 that I just purchased. Should I go with a Dynaco like a PAS or look at another manufacturer? The ST-70 seems to be of original vintage and not modified. It has a PA060 Transformer with cloth leads and A470 's. The other question I have is on the rectifier tube. The one in this unit says "RCA FH" on it. I can not find reference to this tube anywhere, and even though the amp sounds fine, I wonder if I should replace it with a real GZ34? If I do replace the rectifier tube do I have to reset the bias? Thanks for any help. Mike Link to comment Share on other sites More sharing options...
Guy Landau Posted November 24, 2003 Share Posted November 24, 2003 Hey Mike, There are much better options than the PAS. I would prefer a modern preamp to most vintage ones. What is your budget? Some RCA GZ-34's were actually made by Mullard so a photo would help here. Link to comment Share on other sites More sharing options...
Mike Frankel Posted November 24, 2003 Author Share Posted November 24, 2003 Gary: My budget for the pre-amp is around $2-300.00. I will try to take a pic of the RCA tube, and upload it. Thanks Mike Link to comment Share on other sites More sharing options...
Mike Frankel Posted November 24, 2003 Author Share Posted November 24, 2003 Attached is a picture of the Tube that I mention in my first post. I hope someone can heplp me out here wuith both the tube and a recomendation for a Pre-Amp. For details, see my first post on the top of this page. Thanks Again for any possible help. Mike Thanks Link to comment Share on other sites More sharing options...
Guy Landau Posted November 25, 2003 Share Posted November 25, 2003 It looks like a mullard to me, but please check if there's a 2 line production code, etched on the glass envelope near the base of the tube. I think that Dean can help with a preamp recommendation. He had a very good experiencenice with a 6SN7 based, tube preamp from Hong-Kong. Link to comment Share on other sites More sharing options...
Guy Landau Posted November 25, 2003 Share Posted November 25, 2003 This preamp is above your budget http://cgi.audiogon.com/cgi-bin/cl.pl?preatube&1074827926&class&3&4& but it'll be a lot better than a PAS. Link to comment Share on other sites More sharing options...
mobile homeless Posted November 25, 2003 Share Posted November 25, 2003 Also please see below sale on Audiogon of Wright Sound WLA-12a linestage. This is an excellent preamp for the money as well. I have heard this pre in several systems and can recommend it highly. It is always musical, especially with good tube selection and this guy is including a bevy of tubes with the price which is OBO. This is a very nice line stage. Audiogon Ad: Wright Sound WLA-12a Line Stage kh ps - If patient, the best deal on a new pre-made preamp is currently the Lam or BEZ 6SN7 SRPP line stage with full tube rectification. While not on ebay at the moment, one usually comes up. It usually sells for $250 but the wait can be long as it's from HK. Still, I know of no better deal new for what is included. Link to comment Share on other sites More sharing options...
JBryan Posted November 25, 2003 Share Posted November 25, 2003 &classMike, $200 -$300 doesn't give you a lot of options. The Bottlehead Foreplay is an easy recommendation if you're handy with a soldering iron or at least have one. Another pre near your price range is the Philly Audio 7A. Here's one on A'gon for $350 - http://cgi.audiogon.com/cgi-bin/cl.pl?preatube&1074540475&class&3&4& and http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3061128120&category=14974 These suggestions that may be a bit higher than you budgeted but you should still may want check 'em out... The DIVA Classic 1 - http://cgi.audiogon.com/cgi-bin/auc.pl?preatube&1069900381&auc&3&4& VTL Deluxe Preamp w/ phono - http://cgi.audiogon.com/cgi-bin/cl.pl?preatube&1074827926&class&3&4& Audio Note M-Zero Silver - http://cgi.audiogon.com/cgi-bin/cl.pl?preatube&1074637571&3&4& Audio Research SP-9 w/phono - http://cgi.audiogon.com/cgi-bin/cl.pl?preatube&1074631933&class&3&4& Wright Sound WLA12A Linestage - http://cgi.audiogon.com/cgi-bin/cl.pl?preatube&1074522947&class&3&4& Audio Experience SYMPHONIES - http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3060997639&category=14974 YS-Audio Music3 - http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3059977943&category=14974 Counterpoint SA-3000 - http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3060854224&category=14974 CONRAD-JOHNSON PV5 - http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3061120704&category=14974 There's another pre that has been discussed on the forum that shows up on eBay on occasion and there are plenty more opportunities on lessor known brands and DIY pre - just look for ones with high quality part. Keep looking around and you'll find suitable unit in your price range. Have fun -Bryan Link to comment Share on other sites More sharing options...
NOSValves Posted November 25, 2003 Share Posted November 25, 2003 The new Lam 6NS7 SRPP preamp would be a great option in your price range but I would ask Edmund the seller that fabricates them to lower the gain slightly. It will be to high for a ST70 if he lowers it by about 6 - 8Db should be pretty good I talked to him through email before and I'm sure this would be no problem. Craig Link to comment Share on other sites More sharing options...
Mike Frankel Posted November 25, 2003 Author Share Posted November 25, 2003 Guy: I do not see any 2 line production code, etched on the glass envelope near the base of the tube. The only writing at all on the Tube is "RCA" and "FH." right below it. Sorry that I can not add any more info. Thanks all for the recomends on the pre-amp.What do any of you think of the CARVER C-16 SONIC HOLOGRAPHY PREAMPLIFIER? Thanks Mike Link to comment Share on other sites More sharing options...
mobile homeless Posted November 25, 2003 Share Posted November 25, 2003 "What do any of you think of the CARVER C-16 SONIC HOLOGRAPHY PREAMPLIFIER?" Ummmmm... To put it simply, not even in the same ballpark as some of the recs above. There are now a few $300 or so tube preamps that would bring you sound that would render that option pretty second tier (perhaps third tier). This typical solid state preamp is an amazing underachiever and where a lot of the system downfall can occur in my opinion. In the $300 range that are premade, look at: LAM 6SN7 SRPP Line Stage (new) Audio Experience MUSIC MK3 tube line preamplifier To name two. Looking at the build, I think both would be a HUGE step up from the Carver. kh Link to comment Share on other sites More sharing options...
Parrot Posted November 25, 2003 Share Posted November 25, 2003 I recommend the Lam preamp as well. (Not to be confused with Lamm.) Here's a snap of mine, almost ready to fall off the shelf. The most recent one to sell on eBay was this http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=14974&item=3059667220 It went for more than the previous $230, but this included postage, so it's all about the same as that could run $60-$75. If you're interested, just email the seller, and that way you don't even need to wait for an auction. Link to comment Share on other sites More sharing options...
Mike Frankel Posted November 25, 2003 Author Share Posted November 25, 2003 WOW! Thanks!You all have sure given me enough to chew over for the holiday. I will check all of these out and try to hone in on one. Guess the general consensus is to stay away from the Dynaco PAS! Now if I can only solve my tube mystery I will be golden. Thanks Aagain for all the info, and Happy Holiday! Best, Mike Link to comment Share on other sites More sharing options...
Recommended Posts