Hi at all
I have just bought one INT-150 and isnt that a nice amp ?
I think so.
It is intended to drive my two original ESS amt 1C who i bought from new so they are mostly original apart from that i have replaced the internal and external wiring with solid silver wire (teflon flat cabel from an ancient IBM computer made with multicore solid silver) like 2 x 2,8 mm2 (no terminals just directly wired to crossover).
And silver from the crossover to the Heil and the Bass and then i removed the passive bas and filled up with longhaired african "Danish compatible" sheeps wool that really works.
(No sry I cant tell you where my store here in DK got it (he wont tell me) and no there is no more to get, that works it was bought for some of his own developed speakers and he cant get anything like it anymore)
And boosted the bass with 3-6 db at 30-35 hz to lift the missing bottom a little.
And they are fantastic (I think) just the Heils are in need now of replacement diagramphs after like +30 years service i really have to complain to ESS 😀.
ESS AMT-1 AIR Motion Diaphragm buy at hifisound.de
So I have 2 questions to you where hopefully someone can help with an answer or input :
Is it OK to bridge two INT-150 to get the needed +400 W to the ESSs w/o spoiling the quality of the sound ?
Have anyone tried to bridge them to drive similiar loads (like nominal 6 Ohms)
Any input here is appreciated it could also be for the X150.5 that contains the same output stage as far as I have understood.
And finally anyone with experience with quality etc. when replacing the amt diagramphs.
Yeah I know its the Pass Forum but bear in mind that Nelson Pass worked for ESS back in time so maybe I am forgiven ?
or pls. help me find right forum.
I have just bought one INT-150 and isnt that a nice amp ?
I think so.
It is intended to drive my two original ESS amt 1C who i bought from new so they are mostly original apart from that i have replaced the internal and external wiring with solid silver wire (teflon flat cabel from an ancient IBM computer made with multicore solid silver) like 2 x 2,8 mm2 (no terminals just directly wired to crossover).
And silver from the crossover to the Heil and the Bass and then i removed the passive bas and filled up with longhaired african "Danish compatible" sheeps wool that really works.
(No sry I cant tell you where my store here in DK got it (he wont tell me) and no there is no more to get, that works it was bought for some of his own developed speakers and he cant get anything like it anymore)
And boosted the bass with 3-6 db at 30-35 hz to lift the missing bottom a little.
And they are fantastic (I think) just the Heils are in need now of replacement diagramphs after like +30 years service i really have to complain to ESS 😀.
ESS AMT-1 AIR Motion Diaphragm buy at hifisound.de
So I have 2 questions to you where hopefully someone can help with an answer or input :
Is it OK to bridge two INT-150 to get the needed +400 W to the ESSs w/o spoiling the quality of the sound ?
Have anyone tried to bridge them to drive similiar loads (like nominal 6 Ohms)
Any input here is appreciated it could also be for the X150.5 that contains the same output stage as far as I have understood.
And finally anyone with experience with quality etc. when replacing the amt diagramphs.
Yeah I know its the Pass Forum but bear in mind that Nelson Pass worked for ESS back in time so maybe I am forgiven ?
or pls. help me find right forum.
Him has already been very helpfull at the direct mail, but suddenly got busy and then I took the question here to DIY audio so him hopefully could get some relief by the gifted members here 🙂))
We need to keep him in good working condition so we can have him around for many years to come so we need to limit our use of the direct mail to a absolute minimum i suggest.
I did so anyway and because him is maybe to "eager" to answer mails there for his own good, why him is a very nice person, even when a total stranger come around with some questions, i got some very useful help.
But it occurred to me that i was about to draw too much on him than reasonable and then took my remaining questions to here.
also asked pass labs for a service manual cause the amp seem to have gone out of alignment (its not as hot as it should be refering to the user guide when just turned on w/o signal)
And if they can provide me with that i could get an idea if its possible to use the AMP with a nominal 3 ohm (pr. amp) w/o loosing quality if i bridge it.
Just looking at the teory I would need the AMPs to deliver like 25 % more than with the nominal load that is minimun 4 ohm.
So the question could be answered if some body had tried that or/and have access to the schematics and can see how the current limit is made ? if any, may be its just the fuse on the backpanel ?
And there is also the impact on sound quality when you shift the intended working point to another place when the load increases ?
So maybe its not as good an idea but tempting if I could get my hands on one INT-150 more.
But looking around for the above mentioned schematics and manuals gave no result (same for the service manual with adjustment procedure) so i suspect that they are reserved for the authorized dealer techs why i cant find like no nothing anywhere.
So yeah I could just go in and be a dealer for Denmark but must confess i dont have the needed money to do that 🙂)
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can't help regarding Service Manual nor schmtc, irrelevant do I have them, they're not mine to share
however, I can help you with two things
- to determine is your existing amp capable to drive your one speaker properly
-to set what needs to be set, to have proper tem. on heatsinks ( in short - amp behaving as intended)
now tell me , what kind of sources you have?
do you have, by any chance, source with proper balanced output?
if yes, bridging ( both for test and possible future solution) is possible with stereo set of custom XLR cables
however, I can help you with two things
- to determine is your existing amp capable to drive your one speaker properly
-to set what needs to be set, to have proper tem. on heatsinks ( in short - amp behaving as intended)
now tell me , what kind of sources you have?
do you have, by any chance, source with proper balanced output?
if yes, bridging ( both for test and possible future solution) is possible with stereo set of custom XLR cables
well , even in case that you have just SE source(s) , everything can be solved with set of custom RCA to XLR cables
🙂
Baaaad Pa, Mighty ZM again doing all the work!
(ignoring fact that he actually made the Amp........ following logic, with plenty of Wayne's work involved, too)
🙂
Baaaad Pa, Mighty ZM again doing all the work!
(ignoring fact that he actually made the Amp........ following logic, with plenty of Wayne's work involved, too)
🙂)well , even in case that you have just SE source(s) , everything can be solved with set of custom RCA to XLR cables
🙂
Baaaad Pa, Mighty ZM again doing all the work!
(ignoring fact that he actually made the Amp........ following logic, with plenty of Wayne's work involved, too)
Well I already have a old Sentec bridger laying around so i could use that to get started (also still have the 2x Original Sentic PA8 as a curiosity) and have a buffer to counter any impedance issues, but that is intended for unbalanced use.
No as source I am mostly using a Marantz NA7004 that have no balanced output but at the positive side is made with 0 db at 0,775 volts so it should fit the INT150 I suppose.
(just bought a Marantz Na8005 why I could get it cheap and just vent to look in the HIFI stock room and checked but no balanced output on that either)
So it must be the Na7004 that will be used.
Edit just forgot I have a https://hifi-freaks.dk/maerker/audiolab/8300cd-black.html laying around never really used it cause dont like the ESS DACs and this device have balanced out.
I can make the necessary setup to test bridged with one channel on one speaker starting using the Sentic Bridger.
https://www.hifiengine.com/manual_library/sentec/pd-8.shtml Ahh just found it no problem.
So when thats done you suggest to listen or can something usefull be measured inside the INT-150 ?
Edit here we can maybe better use the 8300CD with balanced output ?
BTW
I am taking the INT-150 to a pro (I have like biased 10 AMPs but he have adjusted and biased +1000 so better let him do it and he have the necessary instrument park to check it afterwards to see if it holds spec.
Think best solution is to talk with the guy and hear what he need to adjust (if its not a failure causing the lacking temp) , he could already be one of the guys here and/or already servicing Pass amps so maybe there is really no problem there)
So the only remaining is if there is any sense in bridging 2 INT-150 and the ESS stuff that really belong to another part of this forum.
But anyway thanks for your help, it gets the process started to get some feed back from a likeminded (I suppose) pro like you.
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regarding Iq and other settings, this could help: Pass Labs X150.5 , checking/adjusting offsets ,Iq and gain | Zen Mod Blog
Thank you that was really helpfull !!
The Driver boards seems to be the same as in the INT and it should not be impossible (I sure hope 🙂) to identify the corresponding potmeters on the "main" board
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To round it off:
Good I didnt fire up the car and drove 780 km, used 21k Dkk$, to get the other INT-150 for sale here in DK.
Thx you and wayne saved me some money there.
And to "him" of course
Good I didnt fire up the car and drove 780 km, used 21k Dkk$, to get the other INT-150 for sale here in DK.
Thx you and wayne saved me some money there.
And to "him" of course
everything explained in linked blog post
pretty much same logic - trimpots on UGS modules are for offsets, trimpots besides UGS modules are for Iq, positive and negative halves of amp
Thankfully, Boyz from PL are here to watch us, preventing major ookoops 🙂
Yes that was a little embarrassing must have fallen asleep with open eyes 😛😛 not to remember that a balanced AMP can not be bridged.
That must be a clear symptom of "HUT" syndrome coming from too much Corona isolation and other bad excuses for not using the inside of the head.
Could however have been stubborn and refer to if you use 90 degrees between the phases coming from the 4 amp output you could use a 4 phase transformer and sum the inputs over the iron to one output.
But the cost and overhead to realize that I suspect makes it (much much) easier to just buy or build a 400W AMP from scratch. 😀😀😀
You could however in teory get some more tubelike sound as the result of using a transformer.
😉😉 think I just leave it here before this get to be totally nonsens from my side.
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well, all amps can be bridged, but let these actions for heavy Pros.......
in your case, more complications than needed
I was so concentrated on all things related to input, that I (too) forgot that INT150 is internally proper differential amp .....
in your case, more complications than needed
I was so concentrated on all things related to input, that I (too) forgot that INT150 is internally proper differential amp .....
np (no problem) we got the needed result in the end so a couple of bumps on the road to get there dont make my thx to you any lesser.
Rumor says that you designed the transformer on the INT-150.
Is their an sheild (that can be earted) between primary and secondary winding to counter noise and stuff from mains or how did you fix that ??
(problem using ring core transformers is that they are better transformers than the traditionel H cores and thus can transmit more noise coming from mains through the transformer also cause of closer capasitive coupling in the ring core trafos between primary and secondary)