Not sure how many have found Hammond iron to be grossly out of spec and very poor quality, but.... time to gripe about this junk.
I've been working on a small 45 amp... opted to use a 271X power transformer which is rated at 280-0-280 @ 60ma. With a 40ma load, the secondary is putting out a whopping 320-0-320! It also puts out a huge magnetic field and induces a huge hum output into the output tube. Just taking a flat piece of steel and holding between the power transformer and the output tube drops the hum level significantly.
My brother built a pair of 50-watt monoblocks and used Hammond iron.... the power transformers were so bad you could put a small screwdriver against the core and it held in place while buzzing away. He eventually had to dump them and replace with Dynaclone P782 units... and the amps went from humming to quiet. Hammond is also useless in helping to resolve issues with obviously defective components.
Seriously, Hammond quality varies so broadly I'm starting to think they have monkeys winding the stuff.... not much else can explain just how bad this stuff is. Oddly, I used an Allied transformer (yes, made by Hammond) on the previous amp... same identical layout, chassis size, parts, schematic, etc. and it was dead quiet.
I'm about to swear off anything Hammond... as it's a cr@p-shoot at best and a waste of time to design and build with it. I now have a useless amp due to the high hum level and am debating on building the second amp.
Regards, KM
I've been working on a small 45 amp... opted to use a 271X power transformer which is rated at 280-0-280 @ 60ma. With a 40ma load, the secondary is putting out a whopping 320-0-320! It also puts out a huge magnetic field and induces a huge hum output into the output tube. Just taking a flat piece of steel and holding between the power transformer and the output tube drops the hum level significantly.
My brother built a pair of 50-watt monoblocks and used Hammond iron.... the power transformers were so bad you could put a small screwdriver against the core and it held in place while buzzing away. He eventually had to dump them and replace with Dynaclone P782 units... and the amps went from humming to quiet. Hammond is also useless in helping to resolve issues with obviously defective components.
Seriously, Hammond quality varies so broadly I'm starting to think they have monkeys winding the stuff.... not much else can explain just how bad this stuff is. Oddly, I used an Allied transformer (yes, made by Hammond) on the previous amp... same identical layout, chassis size, parts, schematic, etc. and it was dead quiet.
I'm about to swear off anything Hammond... as it's a cr@p-shoot at best and a waste of time to design and build with it. I now have a useless amp due to the high hum level and am debating on building the second amp.
Regards, KM
Edcor has a pdf up on their forum that has a list of all their previously engineered power transformers. You can certainly find a replacement for that. They made a set of custom power iron for a voltage doubler and the thing is dead quiet.Decent prices, great quality, and made in usa - what more can you ask for?
Hi KM,
Too bad Hammond doesn't work for you. I have used Hammond transformers without trouble for over 30 years. I have even met the late Fred Hammond, I can say that quality is foremost with them.
When I was younger (early teens), I asked for some help with a few projects. I was able to talk to an engineer each time and they were very helpful on each occasion. This was basically Fred Hammond's personality.
Anyway, the Hammond plant is about an hour away from here by car. It is possible they have imported some of these instead of building them here. That might explain your issues. I have no idea if they build everything or import some.
In the end, what do you want us to say? To assist you, or be able to judge the situation, we need the specifics. Things like a complete schematic and pictures above and below the chassis would be expected so that the situation can be completely understood. Otherwise, your complaint has no basis in fact.
I would say the same thing about any complaint where no additional information was given. Just trying to hep you out for future posts for assistance or opinion.
-Chris
Too bad Hammond doesn't work for you. I have used Hammond transformers without trouble for over 30 years. I have even met the late Fred Hammond, I can say that quality is foremost with them.
When I was younger (early teens), I asked for some help with a few projects. I was able to talk to an engineer each time and they were very helpful on each occasion. This was basically Fred Hammond's personality.
Anyway, the Hammond plant is about an hour away from here by car. It is possible they have imported some of these instead of building them here. That might explain your issues. I have no idea if they build everything or import some.
As with any complaint, this depends on how you approach them. An exchange has two sides and it only takes one to mess things up. I wasn't there, so I can't say anything except that your experiences are about opposite to mine.
Did you measure your outlet voltage?
Often you have to rotate the transformer for the lowest radiated hum. If you place sensitive circuitry too near the power supply, you can expect some hum pickup. Placing a shield between the power supply and the circuits is common practice when the spacing is small.
In the end, what do you want us to say? To assist you, or be able to judge the situation, we need the specifics. Things like a complete schematic and pictures above and below the chassis would be expected so that the situation can be completely understood. Otherwise, your complaint has no basis in fact.
I would say the same thing about any complaint where no additional information was given. Just trying to hep you out for future posts for assistance or opinion.
-Chris
Chris,
Your points are well taken... I would agree that Hammond (many years ago) was good stuff in general, but that really doesn't apply to current products. I've used their filament transformers and chokes and these seem fine overall. Still, the small 271X has a much larger magnetic field radiating outward than the Allied unit (also made by Hammond), which was very quiet in the exact same application.
An update.... I Hooked the second 271X up and just put typical loads on the windings. The ratings are:
5.0 VAC @ 2 amps
6.3 VAC @ 2 amps
280-0-280 VAC @ 60ma.
Loads were:
5V4G - 2 amps filament on 5.0 VAC load
3C24 - 3 amps filament on 6.3VAC load (a full amp extra loading)
10K 50-watt resistor across plate winding
I also decided to use a variac to drive the 271X set at 115VAC... line voltage, like most things down here, wanders a bit in South Florida but mine usually hovers around 120VAC.
Even with a bit extra loading beyond the ratings the secondary was sitting at 590VAC. Overall I can live with a bit higher voltage, what escapes me is just how bad the magnetic field is compared to the Allied unit which is the identical size core, end bells, mounting orientation, etc. Here's a couple pics of the first amplifier using the Allied power transformer. It's very quiet compared to using the Hammond 271X.
Regards, KM
PS - my brother was using the 300 series power transformers.... one unit had massive magnetic fields... literally held a screwdriver in place... the other did not exhibit this problem in the identical setup. After replacing them all of his hum problems went away... nothing else was changed. Sorry, but I have to believe that these particular Hammond power transformers had problems.
Your points are well taken... I would agree that Hammond (many years ago) was good stuff in general, but that really doesn't apply to current products. I've used their filament transformers and chokes and these seem fine overall. Still, the small 271X has a much larger magnetic field radiating outward than the Allied unit (also made by Hammond), which was very quiet in the exact same application.
An update.... I Hooked the second 271X up and just put typical loads on the windings. The ratings are:
5.0 VAC @ 2 amps
6.3 VAC @ 2 amps
280-0-280 VAC @ 60ma.
Loads were:
5V4G - 2 amps filament on 5.0 VAC load
3C24 - 3 amps filament on 6.3VAC load (a full amp extra loading)
10K 50-watt resistor across plate winding
I also decided to use a variac to drive the 271X set at 115VAC... line voltage, like most things down here, wanders a bit in South Florida but mine usually hovers around 120VAC.
Even with a bit extra loading beyond the ratings the secondary was sitting at 590VAC. Overall I can live with a bit higher voltage, what escapes me is just how bad the magnetic field is compared to the Allied unit which is the identical size core, end bells, mounting orientation, etc. Here's a couple pics of the first amplifier using the Allied power transformer. It's very quiet compared to using the Hammond 271X.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Regards, KM
PS - my brother was using the 300 series power transformers.... one unit had massive magnetic fields... literally held a screwdriver in place... the other did not exhibit this problem in the identical setup. After replacing them all of his hum problems went away... nothing else was changed. Sorry, but I have to believe that these particular Hammond power transformers had problems.
My experience with Hammond has been the same except that the Magnetic Field part I have not had issues with. But the 115 VAC primary wreaks havoc on the secondary voltages. The current Hammond transformer series needs to be re-labeled as the "Voltage Boost Series".
I had to variac down to 110 VAC a Hammond 278X before my amp blew-up. With Hammonds the bext thing is to under dimension the application and you are sure to get enough voltage and current. If you specify the Hammond in the normal way, somehow these transformers take 120-125 Volts to new height's making DIY an exercise in voltage control, not only B+ but also the tube filaments.
Drawing 4 amps from a 6 amp 6.3 VCT section makes for 7.5 VAC on my Mullard 5-20 amp. With the Variac at 110 VAC I get 6.3 VAC. Go figure....
Then I had a learning curve and was able to implement a Hammond 272JX on an Olson Amplifier design from the 40's with stellar results, and plenty of margin to play with.
I had to variac down to 110 VAC a Hammond 278X before my amp blew-up. With Hammonds the bext thing is to under dimension the application and you are sure to get enough voltage and current. If you specify the Hammond in the normal way, somehow these transformers take 120-125 Volts to new height's making DIY an exercise in voltage control, not only B+ but also the tube filaments.
Drawing 4 amps from a 6 amp 6.3 VCT section makes for 7.5 VAC on my Mullard 5-20 amp. With the Variac at 110 VAC I get 6.3 VAC. Go figure....
Then I had a learning curve and was able to implement a Hammond 272JX on an Olson Amplifier design from the 40's with stellar results, and plenty of margin to play with.
Hi Guys,
Good to know. Have any of you contacted the engineering department through their web site? It might be interesting to know what they say about this. It is entirely possible that their were QC problems and you might end up with free replacements. Can't hurt to go that route, you've nothing to lose. Keep one thing in mind, customer service is there to help you, but they need to be able to quantify what is going on. It's not that they are blocking you, just being cautious in this age litigation and "experts".
Hi kmaier,
Your amplifier really does look like the chassis is too small. Nothing I have is that compact, and that includes amps built by other people. I even have a nice amplifier that someone built in correspondence with Fred Hammond. It's a unit using 7581As that is rated about 20 wpc. Really good sounding amp. I'll try to post a picture of it.
The one thing that was stressed in the old days was to make sure your chassis was large enough. Distance is the best way to fight hum pickup - and lower operating temperatures. If you look at commercial amplifiers, you will see that most are spaced out larger than the one you have made there.
-Chris
Good to know. Have any of you contacted the engineering department through their web site? It might be interesting to know what they say about this. It is entirely possible that their were QC problems and you might end up with free replacements. Can't hurt to go that route, you've nothing to lose. Keep one thing in mind, customer service is there to help you, but they need to be able to quantify what is going on. It's not that they are blocking you, just being cautious in this age litigation and "experts".
Hi kmaier,
Your amplifier really does look like the chassis is too small. Nothing I have is that compact, and that includes amps built by other people. I even have a nice amplifier that someone built in correspondence with Fred Hammond. It's a unit using 7581As that is rated about 20 wpc. Really good sounding amp. I'll try to post a picture of it.
The one thing that was stressed in the old days was to make sure your chassis was large enough. Distance is the best way to fight hum pickup - and lower operating temperatures. If you look at commercial amplifiers, you will see that most are spaced out larger than the one you have made there.
-Chris
Hi,
This one is a Leak Stereo 20. Again, there is a lot of room between components.
Sorry for the lack of quality. These are shot as they are on my shelves. I also have an Eico HF-87 that also shows a lot of room between components.
I guess we are all used to small things these days, but there are benefits to making a larger layout. This is probably even more true for a single ended amp. There is no cancellation happening with these at all.
-Chris
This one is a Leak Stereo 20. Again, there is a lot of room between components.
Sorry for the lack of quality. These are shot as they are on my shelves. I also have an Eico HF-87 that also shows a lot of room between components.
I guess we are all used to small things these days, but there are benefits to making a larger layout. This is probably even more true for a single ended amp. There is no cancellation happening with these at all.
-Chris
Attachments
To play anatech's devil, Hammond's over voltage problem has come up repeatedly here. Every PS tranny I've bought runs high on full load, their primaries windings are no longer representative of common NA house utilities. As have assembly issues. Somewhere I posted pictures of end bells factory installed with hardware cut to length with side cutters. I find them very hit and miss.
PS. nice stuff Chris.
PS. nice stuff Chris.
kmaier said:
I have no idea wassupwiddat. I did a project three years ago using a Hammond power xfmr, and Hammond OPTs. The power xfmr is still working, doesn't seem to have any magnetic problems, and the OPTs tested out as specced. No complaints here.
May be something happened in the mean time that caused QC to deteriorate badly. I didn't use Hammonds on the last project, but rather NOS Stancore's, so no newer Hammonds (except for the ripple filter choke that works just fine) so I don't know. If they're making junk like you describe, then they'd best get their act together before they ruin their rep.
anatech said:
I had a power transformer from them that was so noisy, that in a case, with no load, it was audible across the room with music playing. I emailed them. I got one response asking for my address saying they would sent a new one (to which I responded) and another a couple of days later asking me to ship mine back (which I ignored.) A new one showed up a few days later. I have not, however, plugged it in to find out whether it makes noise, too. But, they were nice about it and helpful.
Hi rdf,
My only concern was that the complaint ought to have relevant information posted as well. We all have seen unhappy customers that turn out to be their own problem. Now we have a more exact picture of what is going on, so we can assess the situation. Otherwise, it's just a complaint without any helpful information.
The fact that there are other people with problems also helps. I haven't, but possibly I will.
Hi dsavitsk,
The reason they wanted the old one back was so they could determine what the problem was. Unless you were to ship it back on your nickel, the part should have been returned. After all, that is normal warranty procedure. If they wanted you to ship it, you may have been able to drop it at one of their distributors instead. The important thing is to allow them to find and fix their problems. not an unreasonable request.
-Chris
Edit:
That Hammond amp is nicely chromed and performs really very well. My favorite amp is still my Eico HF-87.
Here is a better picture of the Leak. I can't find one of the Eico HF-87.
Well, you aren't actually.
My only concern was that the complaint ought to have relevant information posted as well. We all have seen unhappy customers that turn out to be their own problem. Now we have a more exact picture of what is going on, so we can assess the situation. Otherwise, it's just a complaint without any helpful information.
The fact that there are other people with problems also helps. I haven't, but possibly I will.
Hi dsavitsk,
Exactly my point. You listed a complaint and they were able to respond.
The reason they wanted the old one back was so they could determine what the problem was. Unless you were to ship it back on your nickel, the part should have been returned. After all, that is normal warranty procedure. If they wanted you to ship it, you may have been able to drop it at one of their distributors instead. The important thing is to allow them to find and fix their problems. not an unreasonable request.
-Chris
Edit:
Thank you. You should see some other stuff I have, and these when they are cleaned up. I even have a Sansui AU-111 (second prod run) in original condition that needs to be restored. SY has had a look around in the old basement. It was hard to get him out.
That Hammond amp is nicely chromed and performs really very well. My favorite amp is still my Eico HF-87.
Here is a better picture of the Leak. I can't find one of the Eico HF-87.
Attachments
Hi dsavitsk,
Fair enough. I was just pointing out the whys of their interest in the old part. It wasn't about cost. I am surprised they didn't offer to cover the return freight.
Most companies would have you ship the defective one back, then send you out a replacement.
Anyone have a more expensive "Classic Series" transformer that had problems? I'm just wondering if their value products are sourced from off-shore.
-Chris
Fair enough. I was just pointing out the whys of their interest in the old part. It wasn't about cost. I am surprised they didn't offer to cover the return freight.
Most companies would have you ship the defective one back, then send you out a replacement.
Anyone have a more expensive "Classic Series" transformer that had problems? I'm just wondering if their value products are sourced from off-shore.
-Chris
anatech said:
Hi Chris,
Actually, the amplifier in the pics has the Allied power transfomer and the 125ESE Hammond OPT. This amplifier is very quiet... with good tubes, s/n is a solid 80dB below 1-watt output with all AC filaments. Due to the low idling current used with the 45, it's a cool-running chassis sans the power tranformer, the smaller units always run hot.
For some odd reason the 271X just puts out one strong magnetic field in contrast to the Allied unit. I'll admit that the chassis (9x5x2) is on the compact side... by choice actually... it's a scaled-down design from a few years back... price, size and performance, but it's a good-sounding amp.
BTW - some nicely made gear... old Hammond iron. I have some NOS Triad iron which is also nicely made, quiet and hum-free. My recent SET amps were Hashimoto based... slightly larger chassis at 10x6x2. These are dead quiet, their iron is silent and cool running, here's a couple pics:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Regards, KM
The differences in experience may also reflect variances in local utilities. I just walked over to the shop and the Fluke shows 118.3 VAC. Ironically I walked from my Rogers office into a Rogers shop, and looking back at me from Chris's very nice Leak is a Rogers tube. The colours... the colours... 
I have been using Hammond and Allied (also made by Hammond) transformers for a long time. In the last 5 years the output voltage has been creeping slowly upwards on the same model transformers. Yes, the line voltage has increased, and the power lines have become far dirtier due to the increased "electronic" (dirty) loads. Both of these will cause the rectified DC to increase. But I have compared new transformers to a 5 year old version of the exact same model in the same amplifier on the same wall outlet and seen as much as a 10% increase. Just search the forums for the reported B+ voltages that users have been getting on their Simple SE builds over the past 2 years. My first Simple SE with an Allied 6K7VG made 430 volts with a Sovtek 5AR4. My latest one makes 455 volts with the same parts on the same bench (122 volt line voltage). Some users are reporting nearly 500 volts! I have an Allied 6K56VG in a Tubelab SE. It is rated at 550 VCT at 125 mA. I am drawing about 160 mA from it and I measure just over 600 volts. Clearly something has changed.
Some people report issues with buzzing or humming transformers. I have not seen this in years of amp building. Radiated magnetic field will happen with any power transformer, but some are worse than others. Transformers that run a higher flux density because of reduced iron content are often worse than a larger transformer at the same power level, and they tend to run hot. No one can argue that the 200 series Hammonds (and the Allieds) don't get hot. The 300's are cooler and quieter.
The Hammond 200's and especially the Allied's are low cost transformers. They do a good job for the price. Yes, you can get far better transformers, they cost a lot more too. I just wish that they would do a realistic job of specifying the actual output voltage at 120 volts input and stick to the specs. It is hard when you simulate, or calculate everything in a power supply only to wind up with 50 volts too many because the specs are that far off.
In the junk department, does anyone have any idea how to get a 1628SE (not 1628SEA) OPT to pass anything resembling HiFi sound. There is a 20 db notch at 20 KHz that causes a severe HF rolloff starting at 10 KHz and 8 db down at 20 KHz. No amount of creative circuitry or overdoses of NFB will tame it and these transformers are just too clean (and heavy) to use in a guitar amp. They are for now being used as large, heavy B+ chokes. Yes these are junk. The 1628SEA is much better but the Edcors kick their butt.
Some people report issues with buzzing or humming transformers. I have not seen this in years of amp building. Radiated magnetic field will happen with any power transformer, but some are worse than others. Transformers that run a higher flux density because of reduced iron content are often worse than a larger transformer at the same power level, and they tend to run hot. No one can argue that the 200 series Hammonds (and the Allieds) don't get hot. The 300's are cooler and quieter.
The Hammond 200's and especially the Allied's are low cost transformers. They do a good job for the price. Yes, you can get far better transformers, they cost a lot more too. I just wish that they would do a realistic job of specifying the actual output voltage at 120 volts input and stick to the specs. It is hard when you simulate, or calculate everything in a power supply only to wind up with 50 volts too many because the specs are that far off.
In the junk department, does anyone have any idea how to get a 1628SE (not 1628SEA) OPT to pass anything resembling HiFi sound. There is a 20 db notch at 20 KHz that causes a severe HF rolloff starting at 10 KHz and 8 db down at 20 KHz. No amount of creative circuitry or overdoses of NFB will tame it and these transformers are just too clean (and heavy) to use in a guitar amp. They are for now being used as large, heavy B+ chokes. Yes these are junk. The 1628SEA is much better but the Edcors kick their butt.
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