New 183 build

[bepone]

In any case, I'm still going to go for the tube-town OT first. Someone's got to do it. But if it means I'm bringing bacon home for dinner when I should be bringing beef I will look at Merren again, I will DO IT

i'm doing it that way that 2 bolts from OPT are reachable from inside, and 2 bolts i put little bit below the board, so lifting the board 1 cm gives acces to the nut.. so easy to change OPT .

tube town claim that they have good stuff. try to find M6 laminations if they have (it is not cheaper option).
also piemme electra have good stuff it seems, they have M6 because i'm buying from them 10 eur is a shipping means you can take more expensive trafo , comapred to TT.
they also can make everything i get feeling by email correspondence, there is some lab with a lot of equipment on their www.

[Stephen1966]

In any case, I'm still going to go for the tube-town OT first. Someone's got to do it. But if it means I'm bringing bacon home for dinner when I should be bringing beef I will look at Merren again, I will DO IT

i'm doing it that way that 2 bolts from OPT are reachable from inside, and 2 bolts i put little bit below the board, so lifting the board 1 cm gives acces to the nut.. so easy to change OPT .

tube town claim that they have good stuff. try to find M6 laminations if they have (it is not cheaper option).
also piemme electra have good stuff it seems, they have M6 because i'm buying from them 10 eur is a shipping means you can take more expensive trafo , comapred to TT.
they also can make everything i get feeling by email correspondence, there is some lab with a lot of equipment on their www.

Thank you J. I bow to your expertise in this field.

What do you think of this?

120W Push Pull Output Transformer [PP-EI10816CV-N]
2.0k UL40%/4-8-16 Ohm
https://shop.piemme-elektra.it/Categor ... ducts/8166

The datasheet specifies M6T35 Grain oriented magnetic sheet

It has a slightly higher input impedance (2k) as opposed to TT's 1.7k. Forgive my ignorance, but in your view, is this going to significantly affect either the fault tolerance or regulation?

This is the TT Tx: https://www.tube-town.net/ttstore/tt-ou ... plexi.html

Stephen

[WhopperPlate]

Well if you are going for a 183 clone , and you are attempting to hit the mark , I would stick with a transformer that matches the original specifications. I will say it once and I will say it again: plexi otp smacks compared to twin opt. It’s not just the turns ratio that’s different .

[Stephen1966]

Well if you are going for a 183 clone , and you are attempting to hit the mark , I would stick with a transformer that matches the original specifications. I will say it once and I will say it again: plexi otp smacks compared to twin opt. It’s not just the turns ratio that’s different .

Here was an interesting article about the bigger transformer...
https://www.mercurymagnetics.com/premie ... eff-bober/

Thank you Charlie. So you would recommend the Tube Town OT, I guess. Same specs as the Classic Tone #40-18026. Couldn't find a datasheet for the TF-170!

The Tube Town OT does say it is made with 'Grain Oriented Electrical Steel Cores', M6 perhaps - I'm going to contact them to find out more.

[pfarrell]

Does anyone know the mounting centres of the Merren OT?

I built a 183 recently—my first Dumble build with a bunch of help the fine peeps up here. I waited quite some time for the Merren goods...He's pretty busy, YMMV. I don't have any direct comparisons but the amp sounds absolutely awesome to me.

Here's the dims for Merren—since my amp isn't totally buttoned up yet cosmetically—was easy to measure:
PT/ 3 x 3.75" (laydown)
OT/ 3 x 3.25" (standup)
Choke/ ~2.75"

PF-183_23.jpg

[WhopperPlate]

Well if you are going for a 183 clone , and you are attempting to hit the mark , I would stick with a transformer that matches the original specifications. I will say it once and I will say it again: plexi otp smacks compared to twin opt. It’s not just the turns ratio that’s different .

Here was an interesting article about the bigger transformer...
https://www.mercurymagnetics.com/premie ... eff-bober/

Thank you Charlie. So you would recommend the Tube Town OT, I guess. Same specs as the Classic Tone #40-18026. Couldn't find a datasheet for the TF-170!

The Tube Town OT does say it is made with 'Grain Oriented Electrical Steel Cores', M6 perhaps - I'm going to contact them to find out more.

That jumped out at me as well.

Fwiw According to Merren audio website (in reference to his Hiwatt OPT) :

“This is the only reproduction of this transfomer to be using the more costly correct grain oriented core material, responsible for the strong, explosive low frequency response expected from a Hiwatt amp.”

Food for thought

[Stephen1966]

Does anyone know the mounting centres of the Merren OT?

I built a 183 recently—my first Dumble build with a bunch of help the fine peeps up here. I waited quite some time for the Merren goods...He's pretty busy, YMMV. I don't have any direct comparisons but the amp sounds absolutely awesome to me.

Here's the dims for Merren—since my amp isn't totally buttoned up yet cosmetically—was easy to measure:
PT/ 3 x 3.75" (laydown)
OT/ 3 x 3.25" (standup)
Choke/ ~2.75"


PF-183_23.jpg

Thank you! I've read your thread several times. Good job there! Looking good. The OT is a bit different than the Classic Tone then. I don't have the kind of resources to audition lots of transformers here so I think I would just have to live with the work of loosening/removing the board if I wanted to change them. I don't like messing around with solid core though. It will fracture and break if it is bent too much and that kind of problem could be very difficult to find. Great to know these dimensions though, it means I can plan for it at least.

[cys]

I built a 183 recently with a Mercury Magnetics PT and OT. It sounds good but there is something about the sonic signature with this amp that I'm not liking. The discussion in this thread makes me want to try some Merren iron at some point.

I've been searching for the perfect Marshall like sound for a while, mostly moving through boutique Marshall variants. I've been looking for a strong mid grind with singing bass and treble that will breakup when dimed to give fuzz-like distortion that remains "firm with clarity" and not "mushy." The Trainwreck and 183 were part of this search in that I was hoping I could get the general type of breakup I was looking for. As the next step on my search, I recently acquired a 1971 Marshall 1986 that had been converted to 1987 specs with NOS parts. On the one hand it seems simple to observe that "if you want the sound of an old Marshall, buy an old Marshall." Price was kind of a barrier. Also, I was willing to think that modern boutique amps would capture "the" sound and be more reliable. Anyway, this amp is what I've been searching for. Despite the apparent wear and tear on the exterior (understatement), the inside is pristine. The sound is "the" sound (to me).

.

IMG_0754.jpg

[WhopperPlate]

I built a 183 recently with a Mercury Magnetics PT and OT. It sounds good but there is something about the sonic signature with this amp that I'm not liking. The discussion in this thread makes me want to try some Merren iron at some point.

I've been searching for the perfect Marshall like sound for a while, mostly moving through boutique Marshall variants. I've been looking for a strong mid grind with singing bass and treble that will breakup when dimed to give fuzz-like distortion that remains "firm with clarity" and not "mushy." The Trainwreck and 183 were part of this search in that I was hoping I could get the general type of breakup I was looking for. As the next step on my search, I recently acquired a 1971 Marshall 1986 that had been converted to 1987 specs with NOS parts. On the one hand it seems simple to observe that "if you want the sound of an old Marshall, buy an old Marshall." Price was kind of a barrier. Also, I was willing to think that modern boutique amps would capture "the" sound and be more reliable. Anyway, this amp is what I've been searching for. Despite the apparent wear and tear on the exterior (understatement), the inside is pristine. The sound is "the" sound (to me).

.

IMG_0754.jpg

Nothing beats the real thing . phillips iskra piher are going to be hard to beat for what you describe . Those old Dagnal and drakes aren’t going to hurt either . Not exactly dumble

[ijedouglas]

I built a 183 recently with a Mercury Magnetics PT and OT. It sounds good but there is something about the sonic signature with this amp that I'm not liking. The discussion in this thread makes me want to try some Merren iron at some point.

You won't regret it.

Here is a '78 2203 I got for a steal. The outside is a mess but the inside was pristine (except for an EL-34 conversion since reversed) :

dvled6meahzigcpi5sa3.jpg

[Stephen1966]

I built a 183 recently with a Mercury Magnetics PT and OT. It sounds good but there is something about the sonic signature with this amp that I'm not liking. The discussion in this thread makes me want to try some Merren iron at some point.

You won't regret it.

Here is a '78 2203 I got for a steal. The outside is a mess but the inside was pristine (except for an EL-34 conversion since reversed) :

dvled6meahzigcpi5sa3.jpg

That looks great. The Marshall logo is in one piece at least. Will you put it in a new cab?

[bepone]

What do you think of this?

120W Push Pull Output Transformer [PP-EI10816CV-N]
2.0k UL40%/4-8-16 Ohm
https://shop.piemme-elektra.it/Categor ... ducts/8166

The datasheet specifies M6T35 Grain oriented magnetic sheet

It has a slightly higher input impedance (2k) as opposed to TT's 1.7k. Forgive my ignorance, but in your view, is this going to significantly affect either the fault tolerance or regulation?

This is the TT Tx: https://www.tube-town.net/ttstore/tt-ou ... plexi.html

Stephen

the first one looks like for 6L6 but el34 will be ok, no problem for this 10%, both tube types will work. but impressive datasheet with all the parasite parameters which gives another + for pieme!
second is TT GOSS. which indicates higher inductance and good bass, which is also ok!

[Stephen1966]

the first one looks like for 6L6 but el34 will be ok, no problem for this 10%, both tube types will work. but impressive datasheet with all the parasite parameters which gives another + for pieme!
second is TT GOSS. which indicates higher inductance and good bass, which is also ok!

Sorry, what is 'TT GOSS'?

[bepone]

TT - tube town
GOSS - grain oriented silicone steel , can be also M6 code, type of lamination (core)
too long to write

[Stephen1966]

TT - tube town
GOSS - grain oriented silicone steel , can be also M6 code, type of lamination (core)
too long to write

Thank you! Of course Well, I've written to TT this morning asking them about the type of steel they used in the laminates.

The only information I've been able to find about the TF-170 (Dagnall C1998?) is that it was 'Marshall 100w output transformer, 4, 8, 16 ohm, 4 x EL34, 4 x 6550 Primary 1730 ohms, 20-20K HZ' [https://www.google.co.uk/url?sa=t&rct=j ... 2-ZzjNkv2V] Along with some miscellaneous details that it was originally built in England (or Malta - not sure) by Dagnall. Dagnall are still going, but you won't find anything specific about a TF-170 there. The TAD M100A is however, made by Dagnall and uses the M6 core with a primary impedance of 'cca 1k9'. The more knowledgable here seem to think that MrD's TF-170s were actually reissues made by Pacific. If we don't count the outliers that have been wound up in production, there seems to be a lot of good stuff out there which are each very similar. Merren's repro Dagnall C1998 has a primary impedance of (cca) 1k75. I wouldn't count the Hammond 17500U in that collection, the bass looks unimpressive with that one. Merren's Hi-Watt OT looks like a work of art and I think I could only use that and no other, if I were building a HiWatt.

At the moment then, awaiting a response from TT about the laminates, it's a tossup between the three Piemme/TT/or TAD. The TAD seems to offer the right combination of factors but at practically 50% more than the TT and more than the Piemme for that matter as well, I'm not handing over a load of cash just yet! TAD really do overprice stuff, but at least they are consistent.