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ampeg pre-amp revalve


ahpook
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[quote name='ahpook' post='300232' date='Oct 6 2008, 12:39 AM']just ordered a full set of valves for my svp-pro from watford valves.

i'm really looking forward to hearing what they decent valves sound like compared to the no-brand ones that are in there...

i'll let you folks know how i get one

:)[/quote]


What did you buy in the end? I have upgraded both a black face SVP-Pro and a grey hammerite face Ampeg SVP-Pro with valves from Watford Valves and the difference was almost shocking to hear that such poo stock valves are shipped in th epreamps. Sorry Ampeg, just my experience.

Both times I order HARMA Diamond STR drive tested selected ECC83/12ax7's and a personal fave, the Jan-Phillips ECC82/12AU7 (cant remember the model number I am afraid, but Derek Rocco also suggests using them).

You will be very happy with the results.

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[quote name='ahpook' post='304451' date='Oct 11 2008, 04:33 PM']one of the reasons that i plumped for a valve pre and a solid-state power amp ![/quote]


Yeah the irony being that I don't use a single valve in my rig anymore either lol!

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[quote name='dood' post='304566' date='Oct 11 2008, 08:51 PM']What did you buy in the end? I have upgraded both a black face SVP-Pro and a grey hammerite face Ampeg SVP-Pro with valves from Watford Valves and the difference was almost shocking to hear that such poo stock valves are shipped in th epreamps. Sorry Ampeg, just my experience.

Both times I order HARMA Diamond STR drive tested selected ECC83/12ax7's and a personal fave, the Jan-Phillips ECC82/12AU7 (cant remember the model number I am afraid, but Derek Rocco also suggests using them).

You will be very happy with the results.[/quote]

yep...i took derek's advice as well :) (the phillips is a 5814a btw)

the valves it came with were sovtek 12ax7's and a single groove tube 12au7...not sure if they were the stock ones or not.

it's a massive difference in tone. i also can't get over how much louder the pre is as well.

hat's of to watford valves. huzzah !

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[quote name='ahpook' post='304578' date='Oct 11 2008, 09:07 PM']yep...i took derek's advice as well :) (the phillips is a 5814a btw)

the valves it came with were sovtek 12ax7's and a single groove tube 12au7...not sure if they were the stock ones or not.

it's a massive difference in tone. i also can't get over how much louder the pre is as well.

hat's of to watford valves. huzzah ![/quote]


The Sovteks are defintely the stock choice, but not 100% sure about the Groove Tube. I know they use the Groove Tubes valve in the Billy Sheehan BSB preamp though.

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[quote name='dood' post='304594' date='Oct 11 2008, 09:52 PM']The Sovteks are defintely the stock choice, but not 100% sure about the Groove Tube. I know they use the Groove Tubes valve in the Billy Sheehan BSB preamp though.[/quote]

it's going into my dha purist :)

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Hi Mike I think you only have to bias the output stage tubes that are in pairs, so on a SVT3 no problem just change like for like.I have just changed mine in newly aquired SVTPCL that had the same as Marks Pro 3xsovtek 1xgroove tube,though the PRO has 5, so Ithink that must be Ampegs shipping norm, the difference is amazing, harma and philips. Rich :)

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Hi guys,
I have (hopefully) just aquired an SVP-Pro blackface too. From what I'm hearing above it seems like a good idea to think about upgrading the valves. I will have a listen to it first when it arrives and if all seem fine then I may just stick with the stock but I'm always trying to find the best tone possible.

Anyway if I do decide to upgrade then the above mentioned from Watford valves sounds good but I will be wanting a real driving gritty tone if possible from it when I need it. Will this be achievable with most 12au7s like the Phillips? Or should I look for something that has been known for this type of sound?

Cheers.

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[quote name='colinmk' post='307452' date='Oct 15 2008, 10:48 PM']Hi guys,
I have (hopefully) just aquired an SVP-Pro blackface too. From what I'm hearing above it seems like a good idea to think about upgrading the valves. I will have a listen to it first when it arrives and if all seem fine then I may just stick with the stock but I'm always trying to find the best tone possible.

Anyway if I do decide to upgrade then the above mentioned from Watford valves sounds good but I will be wanting a real driving gritty tone if possible from it when I need it. Will this be achievable with most 12au7s like the Phillips? Or should I look for something that has been known for this type of sound?

Cheers.[/quote]

is the 12au7 the 'drive' valve ?

interesting...

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[quote name='ahpook' post='304451' date='Oct 11 2008, 04:33 PM']one of the reasons that i plumped for a valve pre and a solid-state power amp ![/quote]


yeah but U dont have the FEEL of an ALL TUBE POWER AMP- power tubes are where the PUNCH happens IME...... Not trying to start a tube v s.s. war. just my 2c. :)

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[quote name='colinmk' post='307452' date='Oct 15 2008, 10:48 PM']Hi guys,
I have (hopefully) just aquired an SVP-Pro blackface too. From what I'm hearing above it seems like a good idea to think about upgrading the valves. I will have a listen to it first when it arrives and if all seem fine then I may just stick with the stock but I'm always trying to find the best tone possible.

Anyway if I do decide to upgrade then the above mentioned from Watford valves sounds good but I will be wanting a real driving gritty tone if possible from it when I need it. Will this be achievable with most 12au7s like the Phillips? Or should I look for something that has been known for this type of sound?

Cheers.[/quote]

The 12Au7, IIRC isn't part of the drive circuit so probably wont 'add' any additional grit, but the characteristics of one 12au7 tonally may enhance the effect of the perceived grit over another type. I'd have to check the schematic to confirm where the valve sits in the signal chain.

With ref to the blackface, I understand (as I owned one too) that due to their design *some* can suffer from noise getting in to the audio chain. (usually mains hum) - I, like many other found that upgrading to low noise preamp valves improved matters and was very noticeable. As an extra measure, I also bought some shielding cans and fitted and earthed those too. I think they made a bit of difference too.

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[quote name='dood' post='307584' date='Oct 16 2008, 08:34 AM']The 12Au7, IIRC isn't part of the drive circuit so probably wont 'add' any additional grit, but the characteristics of one 12au7 tonally may enhance the effect of the perceived grit over another type. I'd have to check the schematic to confirm where the valve sits in the signal chain.

With ref to the blackface, I understand (as I owned one too) that due to their design *some* can suffer from noise getting in to the audio chain. (usually mains hum) - I, like many other found that upgrading to low noise preamp valves improved matters and was very noticeable. As an extra measure, I also bought some shielding cans and fitted and earthed those too. I think they made a bit of difference too.[/quote]

I see, from looking at the watford website they say their are certain versions of the ECC83/12ax7's that are higher gain. Do you think these would be the choice for the kind of sound I'm looking for? Also am I correct in thinking that replacing valves is as easy as taking the old ones out and the new ones slot in to place? :)

thanks again

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My valve tech called me last night and said that he removed each valve. cleaned all the contacts and put some sort of contact grease stuff on them & says it sounds much better just doing this - he's testing to make sure there's nothing else wrong but is recommending I try it again with just the overall clean up & service carried out.

Worth trying anyway :)

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[quote name='molan' post='307873' date='Oct 16 2008, 01:53 PM']My valve tech called me last night and said that he removed each valve. cleaned all the contacts and put some sort of contact grease stuff on them & says it sounds much better just doing this - he's testing to make sure there's nothing else wrong but is recommending I try it again with just the overall clean up & service carried out.

Worth trying anyway :)[/quote]
Ha!
To borrow a favourite phrase of the missus; told you so! :huh:

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  • 5 months later...

[quote name='colinmk' post='438524' date='Mar 18 2009, 06:09 PM']Anyone know the benefits/differences between normal and cryogenic valves and also what difference would a higher gain harma valve give me, a slightly higher gain valve of the ECC83?[/quote]


One of the guitar magazines did a Cryo Vs Non-Cryo blind test and they heard improvements in tone. I'm not sure what mag it was, but I remember the review.

Yes, a higher gain figure on a valve will give you extra 'gain'.. whether or not that is a good or bad thing (depending on how the valve sounds when it breaks up) is something you may have to try to see if it does what you need.

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[quote name='dood' post='439562' date='Mar 19 2009, 06:43 PM']One of the guitar magazines did a Cryo Vs Non-Cryo blind test and they heard improvements in tone. I'm not sure what mag it was, but I remember the review.

Yes, a higher gain figure on a valve will give you extra 'gain'.. whether or not that is a good or bad thing (depending on how the valve sounds when it breaks up) is something you may have to try to see if it does what you need.[/quote]

Cheers Dood,
Think I'll do without cryo for now since I can get normal for a lot cheaper and I'll go for the standard gain. Yeehaa.

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