73Jazz Posted May 27, 2011 Share Posted May 27, 2011 I spoke with a really good amp tech and after i asked him if there is a difference between both versions, he could only confirm that there is one, but doesn`t know which one. Is a fellow basschatter able to bring light in this darkness? We are talking about those 2 i also checked the layout of both, and the seem to be the same..but this doesn`t mean much^^, as i am a tech noob thanks in advance Quote Link to comment Share on other sites More sharing options...
umph Posted May 27, 2011 Share Posted May 27, 2011 the older one is obviously the best one. From the schematics i have it doesn't look like alot changed really. Quote Link to comment Share on other sites More sharing options...
73Jazz Posted May 27, 2011 Author Share Posted May 27, 2011 i owned a blackface preamp before, but sold it due to getting a Sunn all valve head. I thought i will not need it anymore.So "need" could be interpreted very broadly I love those Ampeg Pre`s and bought an SVT IIP and recently the SVP Pro hammerite one. As i had an awesome tone with the blackface one before and also got great tones out of those two, i started to question if there is a difference between those two SVP Pro´s. what makes the blackface obviously to the best one for you? Quote Link to comment Share on other sites More sharing options...
umph Posted May 27, 2011 Share Posted May 27, 2011 [quote name='73Jazz' post='1247000' date='May 27 2011, 01:03 PM']what makes the blackface obviously to the best one for you?[/quote] sorry was just joking with that part saying older obviously means its better Quote Link to comment Share on other sites More sharing options...
73Jazz Posted May 27, 2011 Author Share Posted May 27, 2011 that is obviously right Quote Link to comment Share on other sites More sharing options...
bigjohn Posted May 27, 2011 Share Posted May 27, 2011 I'd always thought that people complained that the hammerite one was a bit noisy. Though I've never used one so I'm not one of them. I've got blackface model and it's slightly less quiet (not noisy at all) than the SVT-IIP I a/b'd it with, but that was pretty much silent. Though I'd imagine this would vary by each unit as well as (and if at all) by model. Quote Link to comment Share on other sites More sharing options...
Dood Posted May 28, 2011 Share Posted May 28, 2011 [quote name='bigjohn' post='1247189' date='May 27 2011, 03:08 PM']I'd always thought that people complained that the hammerite one was a bit noisy. Though I've never used one so I'm not one of them. I've got blackface model and it's slightly less quiet (not noisy at all) than the SVT-IIP I a/b'd it with, but that was pretty much silent. Though I'd imagine this would vary by each unit as well as (and if at all) by model.[/quote] There's a chap on Talkbass. 'Jerrold Tiers' who works/worked for Ampeg and has written tons of stuff about the SVP on the forum. The hammerite faced version as I understand it featured a different lay out internally due to mains borne noise in the blackface version. However, upgrading to best quality (read as low noise) valves went a long way to cutting down the problem, but I do recall as engineer pointing out that the DI had a hum on my old blackface model. I've also owned a US hammerite unit which was great - yet another thing I sold but wish I could have kept - but that's GAS for you. I can't comment on the physical internal layout as I never owned the two units at the same time to compare. YMMV yahda yahda yahda. Quote Link to comment Share on other sites More sharing options...
73Jazz Posted May 28, 2011 Author Share Posted May 28, 2011 (edited) The hum thing is some kind of interesting. As i wrote before i recently bought the SVP hammerite here on basschat and unfortunately it arrived broke at my door. (But was no real problem,a real gentleman from here sold the unit , so we split up the repair cost to split up the bad thing) So i went to the official Ampeg Dealer here in Cologne to repair it, he has great reputations and after his job is done,he asked if i was aware of that hum thing. As i didn´t hear the unit before i couldn`t say if there was one or not. He told me that all SVP hammerites he repaired at his store has got those humming and it is produced through a factory wrong ground wiring. He could rewire this ground wiring to eliminate this humming. but as the price for this was about 100 GBP i first want to hear it for myself. in my ears this humming is now, after changing a tube, really acceptable and no problem for me, interesting again..i had no humming with the blackface one. But dood named it right GAS took me to buy the blackface one as well..some may call me crazy but i prefer the word collector Maybe i am able to give some information concerning sound difference in a few days. Edited May 28, 2011 by 73Jazz Quote Link to comment Share on other sites More sharing options...
73Jazz Posted June 6, 2011 Author Share Posted June 6, 2011 I spent the last 2 days comparing those 2 units, changed the tubes, listened, changed them again, compared on and on and on.. This is my conclusion: [b]inside/schematics:[/b] according to ampeg pdf`s on their page, both units have the same layout. But if you open both the inside looks significant different. Unfortunately i am an electro-noob so it is only a plate with red blue orange drops on it, don`t know what these are ment to be, but the layout is different and they use different parts on the board. If there is a fellow BC here, who can read those layouts by photograph, i could upload big and clear pictures of the 2 layouts , so you can read them and maybe tell the difference professionally. Just let me know. [b]Sound[/b] Honestly..i spend hours comparing both..i couldn`t hear any remarkable difference. maybe i do not hear good anymore or my ears where "closed" after hours of listening, which i definitely will not exclude. I also did recordings and compared both, i couldn`t tell the difference in a blind test. [b]Hum[/b] as i posted before, there seem to be a construction problem with the SVP pro and grounding, so a lot of people have great hum problems with the unit. Some could eliminate those problems by changing the tubes, some don`t. I think it is also a question of perception, what for one means a lot of hum is some kind of quiet to another one. But here is a difference in both units! The blackface one is really quiet and the hammerite one has a noticeable, and for some annoying, hum. Maybe this is because fo the different inside layout of both units..i regrettably do not know, cause i am no technician. But with the same tubes on same position the blackface SVP is definitely more quiet than the hammerite one. I read about some kind of trick to reduce that hum using also a 12AU7 in position V5 instead of 12AX7, but this is some kind of trick to yourself and noone else. The 12AU7 has 70 percent of the volume/gain of the 12AX7, so of course if you change it, it is more quiet^^ but if you turn up the volume to the same level as with the 12ax7 you have the same hum.YMMV I also wrote a mail to AMPEG and asked if they may help me with this question..if i get a response (what i do not believe:) ) I will let you know Quote Link to comment Share on other sites More sharing options...
bigjohn Posted June 6, 2011 Share Posted June 6, 2011 Interesting... So Ampeg changed the layout to get rid of the hum (that I can't hear) which made it worse! I wonder when the hammerite one came into production... And if it had anything to do with SLM? Quote Link to comment Share on other sites More sharing options...
paul_5 Posted June 6, 2011 Share Posted June 6, 2011 (edited) i've got a blackface svp and the di out has some hum on it. Whether it's due to a replacement transformer (now made in china) i'm not sure. When i switch the di output from pre to post eq then the hum disappears. Mine is a little noisy, but i can confirm that fitting a 12AU7 at v5 definately reduces the overall noise floor. I tend to do this when i'm using it to record through the preamp outputs as opposed to the balanced di, as i fine it gives a more 'tubey' sound - i don't think the di has all of the valves in its circuit. Hope this is of use to someone. Edited June 6, 2011 by paul_5 Quote Link to comment Share on other sites More sharing options...
73Jazz Posted June 7, 2011 Author Share Posted June 7, 2011 (edited) There is an interesting detail i didn`t recognized so far. There are 2 different versions of the SVP hammerite. One has the tuner out on the right sight of DI out facing back panel and one left. That one with with tuner out left is the newer one and as i looked at pictures the di out is without volume knob as well. I compared the older hammerite SVP with the blackface and maybe this is just some kind of face lift version. Edited June 7, 2011 by 73Jazz Quote Link to comment Share on other sites More sharing options...
73Jazz Posted June 7, 2011 Author Share Posted June 7, 2011 [quote name='bigjohn' post='1258439' date='Jun 6 2011, 03:58 PM']I wonder when the hammerite one came into production[/quote] Open for correction, if i see it right The blackface came 1990. 1995 the hammerite with Di out right side of tuner out and 1999 the non adjustable DI out left of tuner out version. Quote Link to comment Share on other sites More sharing options...
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