thought's on vintage 'iron' and voltages

[Bombacaototal]

the old two rocks transformers and parts selection were nothing special...

I think the Classic Tone transformers (as used by Two Rock during the time of the Sig) are great....Why do you think they are not good?

[norburybrook]

the old two rocks transformers and parts selection were nothing special...

I think the Classic Tone transformers (as used by Two Rock during the time of the Sig) are great....Why do you think they are not good?

he said they're not 'special'. That's what we're talking about here. My friend said the two rock amps weren't anything special, my one was, and my thoughts went to the transformers and higher voltages.


M

[martin manning]

Marcus, another experiment you could do is Variac your input voltage down 10% or so and see what that does to the sound.

[Bombacaototal]

the old two rocks transformers and parts selection were nothing special...

I think the Classic Tone transformers (as used by Two Rock during the time of the Sig) are great....Why do you think they are not good?

he said they're not 'special'. That's what we're talking about here. My friend said the two rock amps weren't anything special, my one was, and my thoughts went to the transformers and higher voltages.


M

Sorry to derail Marcus but I was genuinely interested as the Classic Tone are the ones I am going for usually. I thought about vintage but I like the flexibility of the taps both on PT and OT and hence why I usually opted for the new trannies..

But this thread got me thinking about maybe going Vintage..

[norburybrook]

Rafael, the peavey had 4-8-16 ohm taps, they were taped off but it was easy to connect new leads. The power transformer needed a FWB rectifier but that was just a simple adjustment of the diodes with a little help from Martin. It does give you ~500vDC



M

[Bombacaototal]

Rafael, the peavey had 4-8-16 ohm taps, they were taped off but it was easy to connect new leads. The power transformer needed a FWB rectifier but that was just a simple adjustment of the diodes with a little help from Martin. It does give you ~500vDC



M

That is great to know! Thanks Marcus

[Bombacaototal]

By the way Marcus, which Peavey amp was the donor for those trannies

[talbany]

I've built all different kinds of amps with just about every popular power transformer out there. Hammonds, Schumacher,Heybours,Partridge,Classictones, All different kinds of Mercury's,Drakes, Edcor, Pacific, Stancor, Triad's. Peavey's Musicman and even cheap China Webers (whoever made those). Some were FWB some just FW and Tube rectified and a few regulated using an Oc3 ala Hammond organ.

In all my experimenting around and auditioning power transformers yielded interesting results and just when I thought I'd found the right one I would build another one that was just as good and some were spectacular sounding using a different transformer brand or type. I've built some really inspiring sounding amps with some of the cheaper generic replacement transformers and some not so great ones using high priced Mercury's or even Schumacher's. Although I can usually feel the difference between a fresh power transformer and one that has many hours on it most cannot tell and even if they could they might not like the sound and feel of an older well worn in power transformer. Which is better? It's totally up to whatever that player likes or wants. The next guy comes along picks the other one, go figure. Types of Steel,Copper, Power handling, Multiple primary taps, Voltages under load, amp ratings, Regulation, Parasitic bias supplies, Bias taps,FWB,FW,Tube rectifiers and the overall amp design. These things all in some way shape the sound and feel of the amplifier (along with the power supply filters). In the end which one of these transformer types will be universally loved by all. None of them. You might find the right combination that you think is perfect and someone else will come along and pick the amp loaded with the cheap China Webers. So after all that rambling on about transformers IMO it's the total sum of everything and all those tolerances that come together to generate a unique sound that that player admires for whatever reason,or it can come together to sound like a not so great instrument. Just like I've played my fair share of Vintage instruments that were dogs that no great set of pickups can help. If you are an amp manufacturer there are many other things to consider as well. Quality control, Warranty, Reliability, durability, Safety standards,COST!!etc etc. Bottom line: as long as you use a well respected high-quality brand name power X-former that meets the required voltages and specifications pay attention to the details ie quality filter caps,layout and lead=dress circuit constants patience and some tender loving care (Follow my Layouts ).You should no doubt end up with a fine sounding guitar amplifier to be proud of.If other people like it great if they don't who cares it's not their amp.
Output transformers are another story.
IMO. There is no special mojo hiding somewhere deep inside a set of Peavey Transformers.

Tony

[Bombacaototal]

The single 1x12 classic lead 80 didn't sound that much different to the 2x12 G12 -65's , it handled the 100w JM amp too dimed, as I said I did start to worry so swapped to the 2x12...

M

Marcus, I have a naive question relating to the power handling of the speakers. It is my understanding that the JM Sig is a very low gain and quiet amp for 100W. I was wondering if because of that a 80W speaker would be more than enough to handle this amp? Similarly would a very gainy and loud 50W amp need a higher rated speaker than 50W? Or the gain and amount of sound an amp produces and the OT rating are unrelated and therefore the latter will determine the speaker rating?

[Max]

... made from 18mm plywood ...

Just to avoid misunderstandings: AFAIR most original Dumble speaker cabinets have lumber core plywood sides (around 3/4") and a (AFAIR 5 layer) plywood front and back (around 1/2"). BTW: Up to now I've never seen an original "baltic birch plywood" Dumble cabinet.

Lumber Core Plywood: https://iketrading.com/index.php/produc ... umber-core

Cheers,

Max

[norburybrook]

... made from 18mm plywood ...

Just to avoid misunderstandings: AFAIR most original Dumble speaker cabinets have lumber core plywood sides (around 3/4") and a (AFAIR 5 layer) plywood front and back (around 1/2"). BTW: Up to now I've never seen an original "baltic birch plywood" Dumble cabinet.

Lumber Core Plywood: https://iketrading.com/index.php/produc ... umber-core

Cheers,

Max

Interesting I'm not one who thinks that that would really make any significant difference to the sound though I mean he used paper packing tubes for the ports on the 1x12 cabs,as Joe Bonamassa found out when he bought one and took it apart

M

[norburybrook]

The single 1x12 classic lead 80 didn't sound that much different to the 2x12 G12 -65's , it handled the 100w JM amp too dimed, as I said I did start to worry so swapped to the 2x12...

M

Marcus, I have a naive question relating to the power handling of the speakers. It is my understanding that the JM Sig is a very low gain and quiet amp for 100W. I was wondering if because of that a 80W speaker would be more than enough to handle this amp? Similarly would a very gainy and loud 50W amp need a higher rated speaker than 50W? Or the gain and amount of sound an amp produces and the OT rating are unrelated and therefore the latter will determine the speaker rating?

the JM sig isn't a loud 100w am by any means but it's fairly loud and pushing an 80w speaker just felt like pushing the envelope too far fro comfort even though sonically it was fine. I think JM uses two 2x12 Alexandro cabs/amp in his live rig.

My friend uses a 50w #102 into a 1x12 classic lead 80 and hasn't had issues and he plays loud, he did blow up an EVM 12 with the 100w Bluesmaster thouigh



M

[Mr. dB]

Interesting I'm not one who thinks that that would really make any significant difference to the sound though I mean he used paper packing tubes for the ports on the 1x12 cabs,as Joe Bonamassa found out when he bought one and took it apart

Everyone did in the 1970s. Look at a JBL from that time for example...

[talbany]

... made from 18mm plywood ...

Just to avoid misunderstandings: AFAIR most original Dumble speaker cabinets have lumber core plywood sides (around 3/4") and a (AFAIR 5 layer) plywood front and back (around 1/2"). BTW: Up to now I've never seen an original "baltic birch plywood" Dumble cabinet.

Lumber Core Plywood: https://iketrading.com/index.php/produc ... umber-core

Cheers,

Max

Interesting I'm not one who thinks that that would really make any significant difference to the sound though I mean he used paper packing tubes for the ports on the 1x12 cabs,as Joe Bonamassa found out when he bought one and took it apart

M

Marcus.
I don't know if the cabinet played a role in your sound test? Who knows. I will share my experience with different kinds of cabinets using the same speakers.
When we were designing our Cabinet for the Lindy Fralin Model amp (narrow panel style) our cabinet maker built 3 identical combo cabs using 3 different types of woods for us to audition Baltic/Sand Ply/ Standard cheap cabinet grade ply?. I was surprised at the difference each sounded. I also have a 1949 Tweed pro that is the same size as our Fralin amp loaded same speaker and sounds noticeably different than the Fralin cabinet which BTW sounds great with just about any amp attached to it. Something about how that old dried wood just seems to resonate at all the right frequencies. BTW Paper ports have been used in ported speaker cabinet designs for Eons

Ports are like sex. it's the size and depth that matters most.

Tony

[norburybrook]

Just to avoid misunderstandings: AFAIR most original Dumble speaker cabinets have lumber core plywood sides (around 3/4") and a (AFAIR 5 layer) plywood front and back (around 1/2"). BTW: Up to now I've never seen an original "baltic birch plywood" Dumble cabinet.

Lumber Core Plywood: https://iketrading.com/index.php/produc ... umber-core

Cheers,

Max

Interesting I'm not one who thinks that that would really make any significant difference to the sound though I mean he used paper packing tubes for the ports on the 1x12 cabs,as Joe Bonamassa found out when he bought one and took it apart

M

Marcus.
I don't know if the cabinet played a role in your sound test? Who knows. I will share my experience with different kinds of cabinets using the same speakers.
When we were designing our Cabinet for the Lindy Fralin Model amp (narrow panel style) our cabinet maker built 3 identical combo cabs using 3 different types of woods for us to audition Baltic/Sand Ply/ Standard cheap cabinet grade ply?. I was surprised at the difference each sounded. I also have a 1949 Tweed pro that is the same size as our Fralin amp loaded same speaker and sounds noticeably different than the Fralin cabinet which BTW sounds great with just about any amp attached to it. Something about how that old dried wood just seems to resonate at all the right frequencies. BTW Paper ports have been used in ported speaker cabinet designs for Eons

Ports are like sex. it's the size and depth that matters most.

Tony

LOL

Tony I'm quite prepared to accept that, I guess I seem to be very lucky with my choices though and in some ways I find it quite perturbing as I never know exactly why one of my amps/speakers sounds so good when players try them! and for those reasons I'm glad I'm not making them commercially

M